Dominions 3: The Awakening/Nations/R'lyeh, Time of Aboleths

Before the Great City fell and destroyed their capital, the Aboleths ruled the seas. While the bulk of R'lyeh's armies are still shambler and Atlantean slaves, their elite units and commanders are Aboleths of various ages. The oldest Aboleths are extremely skilled in both water and astral magic.

Overview
EA-R'lyeh is an underwater nation strong in Astral and Water magic, with access to weak Earth, Nature and Death. You also have several types of aquatic mind-blaster units and commanders, none of whom can go on land without magic. These mind attacks are EA-R'lyeh's answer to the two other aquatic nations who generally have access to stronger units. Your magi are pricey and non-sacred, so upkeep costs become an issue. Most of R'lyeh's units and commanders have Darkvision which gives them quite an advantage in battle when operating in Darkness. With reduced equipment slots and the expense of getting your most powerful magi onto land, EA-R'lyeh depends heavily on amphibious communions of slave magi to make the nation viable. Arguably a late bloomer, EA-R'lyeh will likely struggle in the early game till advanced research can leverage the nation's full potential.
 * Strengths:
 * Very strong astral and water magic
 * All your national magi include astral, can join communions, which allows powerful battle magic without expensive booster forging
 * Mindblaster units and commanders recruitable on turn-1
 * Darkvision troops, many who have decent combat stats, some are mindless
 * Hordes of low-cost melee troops can be quickly recruited
 * Being an Underwater nation gives you some early-game security against neighbors
 * Freespawn aquatic chaff troops


 * Weaknesses:
 * Weak PD
 * Only indie troops and commanders recruit-able on dry land, no national units or commanders
 * Magic leadership needed for some troops, complicates army organization and interferes with research
 * Non-lobo troops have low-morale
 * On land your troops are slow and vulnerable to missiles
 * Best commanders are Aquatic and/or 0-movement, all with only 2 equipment slots
 * Very limited choices for pretender chassis

Units
All of R'lyeh's slave troops suffer from low morale. Sermon of Courage or a Horn of Valor are needed to keep them steady in tough fights. All slave types mirror Oceanian or Atlantian counterparts, and come in "light" and "heavy " versions. On land, R'lyeh suffers from lack of shield troops. However this is not insurmountable since indie Ichtyid Warriors are fairly common underwater you can use those if you need shields.

R'lyeh's lobo-troops, mindblasters and freespawns all require magical leadership, making large army organization require special attention throughout the early game lest your research stumbles.

Light Slave Troops

 * Slave Trooper (Triton): Gold 9, Resources 2, Spear
 * Unarmored aquatic-only chaff trooper. They have 50% more hp and better combat stats than their indie counterparts, and you can buy them in droves. When stacked with mages in a communion casting Mass Protection and Strength of Giants they make decent UW chaff. One of the biggest problems I have with aquatic-only troops is they become an economic liability once the underwater conquest is complete, being unable to ever leave the water.


 * Slave Trooper (Merman): Gold 9, Resources 3, Spear, Net
 * Net-wielding unarmored amphibious chaff trooper, otherwise nothing remarkable. They are your quickest troops and tend to arrive just ahead of other mermen or triton forces. On land, they fight as poor amphibians... a huge disadvantage. They are quite squishy and run away easily, but their net attack can disable an enemy for a round while heavier troops land hits, thus mixing a few of these guys in with a stack of Triton Guards can sometimes work ok. I've also seen a swarm of these guys mob an SC (underwater) and bring it down while taking only minimum losses due to their nets. They form a major part of your PD both above and below the waves, so you might as well try and use that to your tactical advantage.


 * Slave Trooper (Atlantean): Gold 9, Resources 3, Trident, Darkvision
 * Unarmored amphibious chaff trooper. Slightly less hp and combat stats than the triton slaves and twice as slow, but they are armed with a trident, can leave the sea and fight equally well both above and below the waves. Slow can sometimes be a tactical asset, as these guys tend to engage the flanks or rear once battle has been joined. Much like the triton slave trooper, they work best once buffed with magic. Their darkvision offers some interesting possibilities in battle with a Darkness spell.

Heavy Slave Troops

 * Slave Guardian (Triton): Gold 9, Resources 13, Trident, Shell Armor, Iron Cap
 * These are your best heavy troops, but are aquatic-only. In that role, they perform admirably. The only downsides are poor morale as mentioned previously and being unable to leave the sea.


 * Slave Guardian (Merman): Gold 9, Resources 12, Spear, Shell Armor, Iron Cap
 * Less hp and weaker combat stats than your tritons, plus only armed with a spear. Poor amphibians on land. I honestly have never found a use for these guys for any reason.


 * Slave Guardian (Atlantean): Gold 9, Resources 13, Trident, Shell Armor, Iron Cap, Darkvision
 * Slightly less stats than the triton guardian and much slower, but they are amphibious. Their trident attack + 12 str enables pretty decent damage-output as compared to most other size-2 land troops. On land they get mapmove-2 which classes them as medium infantry in my book. Primary weaknesses are low morale, slow movement (slower than indie HI) and no shield, making them vulnerable to missile fire without magic protection. Once the oceans are secure, these troops tend to become the de-facto mainstay of R'lyeh's armies. Darkvision offers some interesting combat potential.

Lobotomized Troops

 * Lobo Guard: Gold 5, Resource 1, Claw, Magic Being, Amphibian, Mindless, Darkvision
 * Being extremely cheap and low resource, these represent an interesting alternative as chaff troops. R'lyeh can muster dozens of these each turn when necessary, but being magical they need a mage to lead them into battle. They never run away and fight to the death, which is likely since they go into battle stark naked. On land, they are also vulnerable to archers. That said, their 12 strength means the claw attack does almost as much damage as a spear-wielding merman. Use magic to improve their strength and defense, and you have the makings of reliable, if squishy, light infantry. Especially when fighting under a darkness spell.


 * Shambler Thrall: Gold 25, Resource 1, Claw, Magic Being, Amphibian, Mindless, Trample, Darkvision
 * Like the lobo guard, these guys require magic leadership and fight to the death. 5x more expensive than lobos, but much higher hp, better prot and the trample ability. They are only size 3, so trampling makes them tire quickly. But groups of your S magi can turn a few dozen of these guys ethereal, which makes them very tough to kill. Darkvision offers some interesting possibilities in battle under a Darkness spell.

Mind Blaster Troops

 * Giboleth: Gold 40, Resource 1, Tentacle x2, Mind Blast, Aquatic, Magic Being, Darkvision
 * Recruit-able in any fort, the role of these large fish is to hang back in battle, thinning-out enemy forces with their paralyzing mind blast while your other troops do the killing. One frustrating aspect of this is there is no guarantee they won't choose a target that isn't already paralyzed, hence used in large numbers there tends to be diminishing returns. Their combat stats are not stellar and they are size-3, so once their 10 mind blast charges run out, they slowly crawl into melee and tend to get into trouble. That said, they prove very useful even against undead armies, since they ignore the mindless chaff units and target the commanders instead! Magic 2-3 scales lower enemy MR vs mind blast. They can never leave the sea.


 * Gibodai: Gold 60, Resource 1, Life Drain, Mind Blast, Aquatic, Magic Being, Darkvision, Sacred
 * A sacred cap-only version of a Giboleth, which limits the number you can recruit per turn in spite of their low-resource cost. Although more expensive that Giboleths, they cost less upkeep, and pay for themselves after about 2 years. The life drain attack steals health, so combined with the right bless, they can prove to be much more durable in melee than their giboleth brethren.

Freespawn

 * Polypal Spawn: free auto-spawn, weak AP tentacle attack, Aquatic, Magic Being, Darkvision
 * These guys spawn automatically in any friendly underwater province with positive candles where there is a Polypal Mother commander. The amount of spawns/turn is randomized but the max depends on the number of friendly candles, usually ranging from 1-4 per mother. You would think that this would become a useful part of any EA-R'lyeh strategy: massive swarms of freespawn chaff similar to EA-Pangaea's Manaeds. By mid-game you might even have enough spawns to try that. However unlike Maneads, Polypal Spawns are non-sacred underwater-only meatbags that rarely do any damage when they hit, and they never stop spawning in friendly dominion. Their combat stats are mediocre, their morale low, and their low strength and weak tentacle weapon means they hardly ever do any damage, but hey, it's free chaff right? Arguably they are most useful in the early stages of the game when even a dozen free units can help kite enemy troops to break tough indies. At size-1 they deploy six per square so are at their most effective when they vastly outnumber the enemy. Buff spells like Strength of Giants mildly improves their combat effectiveness (ie. they go from useless meatbag decoys to squishy light troops). A Darkness spell helps their effectiveness quite a bit against non-darkvision troops. Each Polypal Spawn requires no gold upkeep but eats 0.5 food per turn. Assuming they are being spawned in kelp fortresses located in your key provinces, this can lead to logistical problems due to starvation during a siege or late-game, because they never stop spawning even when you no longer want/need more. Hence you should come up with a plan to dispose of your excess polypal spawns (dump them in a low-food province to starve), kill off or locate your polypal mothers in enemy dominion, etc.
 * Note: Polypal spawns that die from starvation do not create corpses in a province.

Commanders

 * Scout: Gold 20, Resources 1, Coral Knife, Amphibian, Stealthy, Darkvision (50)
 * An amphibious scout. The poisoned blade of the coral knife is afaik considered magic for purposes of attacking ethereal units. Any advantages from Darkvision will probably rarely come into play.


 * Slave Prince: Gold 60, Resource 20, Trident, Iron Cap, Scale Mail Hauberk, Amphibian, Darkvision (50)
 * High leadership, high hp, high strength, and better-than-average morale. Overall a good commander unit for your slave-troop armies. It's stats are high enough to consider thugging it out using magic buffs or limited forged items. One easy possibility is to stand them in the same square as a friendly S mage set to cast Body Ethereal: the spell takes effect on both commanders. Useful magic kit includes a Horn of Valor, which will help prevent your endemically low-morale units from running.


 * Slave Priest: H1, Gold 65, Resource 1, Magic Staff, Sacred, Amphibian
 * This guy actually has an above-average def skill (12) for a chaff priest commander. With their magic staff and sacred status, it almost begs taking a high W bless just to see if they can be leveraged as cheap mini-thugs.


 * Slave Mage: W2S1+(N/E/S/W 100%), Gold 175, Resource 1, Research 6, Magic Staff, Amphibian
 * EA-R'lyeh's bread-and-butter mage for research, communion slaves and some important E/N magic diversification. Interestingly they also have a decent def of 14, which can be further raised with Quicken Self. Their gold price for research output is by no means cheap, essentially rendering R'lyeh as a mediocre research power, hence one reason why Magic scales are a good idea. Upkeep is 11 gold/turn which quickly adds up as well. Your slave magi lose 1 W pick on land, but thereby gain a feet slot, which is annoying but by no means insurmountable, since they all have S picks and can join a communion if necessary to boost their paths. This saves a huge amount of gems that would otherwise be needed for forging magic boosters. When summoned and employed in sufficient numbers, communions should enable them to cast any battlefield W/S/N/E spell as necessary. Some likely communion spells:
 * W2S2 - on land can be easily boosted to W1S4 using PotS and LotNS for Soul Slay or Enslave Mind.
 * W3S1 - on land can be boosted back to W3S2 using PotS for Falling Frost, Mindburn or Paralysis.
 * W2E1S1 - on land boost them to W1E3S2 using PotS and Earth Power for Strength of Giants, Destruction, Legions of Steel, Bladewind as well as Mindburn or Paralysis.
 * W2S1N1 - on land boost them to W2S2N2 using PotS for Sleep, Panic, Beserkers or use them as Communion Master to get into Regeneration, Mass Protection, Foul Vapours, etc.
 * As well, all your Slave Magi can cast Body Ethereal at Alt-3, an AoE-1 spell which when spammed amongst your stationary troops at the beginning of battle makes them much tougher to hit.
 * When combo-ing your Slave Magi with Darkvision troops and Darkness on the battlefield, use spells like Frozen Heart which always hits the target.


 * Polypal Mother: H2, Gold 100, Resource 1, Life Drain, Mind Blast x2, Sacred, Aquatic, Poison Immune, Need not Eat, Magic Being, Blind
 * At first glance pretty interesting stats, but this proves to be probably one of EA R'lyeh's strangest units and most difficult to fit into any coherent strategy. One of the main factors limiting it's use is their immobility: without empowerment into S magic (which would be insane), they can never move from their home province, thereby rendering their use as purely defensive. Another factor is their aquatic nature, limiting their deployment to underwater provinces within a fortress (no point in giving Amulet of the Fish to a commander that can't move). A third is the auto-spawning feature of Polypal Spawns depending upon the current strength of friendly dominion in the province where a Polypal Mother is located. In castle defense, once the Mother's mindblast attacks run out, they are most likely to spam Sermon of Courage. But raising their holy magic to H3 to enable Smite using crystal matrices and a master casting Power of the Spheres might work. Perhaps another way to meaningfully deploy them could be in key border provinces having strong adjacent enemy dominion, then have the Polypal Mother simply stop Preaching when you no longer want any new spawns and allow the dominion there to fall back into negative candles.


 * Aboleth: W2S2+(W/E/S/D 100%), Gold 200, Resources 1, Research 7, Life Drain x2, Mind Blast, Aquatic, Magic Being, Darkvision
 * The eponymous mind-blaster namesake unit one expects to find from anything named R'lyeh. This is their Age, the Time of Aboleths. So what is there it brag about? Good hp, high MR, some access to D/E magic and S3 casters. Upkeep 14 gold/turn and 3 food, the slave Magi are more cost-effective researchers. The limitations of Aquatic and only 2 misc slots is pretty severe. Likely kit is a Spell Focus (S1) or Eye of the Void with Amulet of the Fish (if you can forge them) on land, maybe a W/S booster or an Amulet of Anti-magic underwater. There is a lot of overlap between the role the Aboleth plays in R'lyeh's lineup and what the Giboleth/Gibodai units can do. So the Aboleth is really mostly necessary for it's magic buffs... but in that sense Mind Lords (who have stronger paths) or Slave Magi (who have more equipment slots) buff the same magic just as well, if not better, begging the question why bother with Aboleths at all? There is a very niche use for D-random Aboleths joined in a communion casting Wither Bones (Thaum-6 D3) if you are fighting an Undead nation. Also, their magic leadership skill starts at 125, so they are quite capable at moving around large numbers of lobos.


 * Mind Lord: W3S3+(W/E/S/D 100% W/E/S/D 10%), Gold 420, Resources 1, Research 9, Soul Leech, Enslave Mind, Aquatic, Magic Being, Darkvision
 * The Mind Lord has the highest research/gold cost of all your magi, but also the highest likelihood of bestowing you with a coven of S4 mind-hunting casters (1-in-40 Mind Lords will have S5). A D-random ML out site-searching will discover all underwater W/S sites, and most of any available D sites (there is one underwater site that requires D2 to find). It shares the Aboleth's downsides of Aquatic-only and limited equipment slots. Being non-sacred, they cost a whopping 28 gold upkeep per turn and require 5 food, making them expensive commanders to horde in large numbers. Whereas the Aboleth paralyzes its targets, the Mind Lord enslaves enemies and converts them to friendly units. This is certainly a useful ability to have on turn 1, especially if there are any indie Sea Trolls or Kraken around. But you only get 5 free casts before the Mind Lord needs to be scripted to do something else, or the AI will likely move it to the front line to engage in melee. Soul Leach is effectively an AoE-1 AN lifedrain attack, which like a vampire gives the Mind Lord a hp boost that carries over into future turns. A D-random mind Lord would probably make a good chassis for a semi-SC prophet in the early game, as it will have plenty of hp and be able to reanimate undead corpses for free. Since they don't come with a body slot, prophetising is the only way to get a Mind Lord to benefit from any pretender bless.

Heroes
R'lyeh only has one hero in this age. If you take a Misfortune scale, you likely will never see him, while a Luck scale might find him at your gates quite early.
 * Auluuhd the Mind Lord: W4S4 aquatic, magic being, darkvision(100); hp:99 prot:2 mor:13 MR:20 str:15 att:10 def:14 prc:10 mv:2/5 ldr:10. Basically a souped-up version of a Mind Lord, but he could very well be your best mage for empowerment to cast certain rituals.

Starting Sites

 * The Gorge of Ancient Cities:
 * Produces 3S, 2W, 1E gems/turn
 * Enables recruitment of Mind Lord and Gibodai

National Spells
None. However, it should be pointed out that every single one of your national magi has S picks, making Communion Master and Communion Slave EA-R'lyeh's de-facto national spells. EA-R'lyeh needs to leverage its strong Astral across the board to make up for it's many weaknesses and have a chance at winning.

National Summons
None. It should however be said that as an underwater nation, R'lyeh's summons are limited till you can establish a foothold on a land province with a lab. Hence, having access to reliable underwater summons should be a core part of your strategy:
 * Underwater Commanders
 * Contact Naiad W3N1 Conj-5 Uses W gems to break into strong N magic, and you will easily have enough W/N slave-magi randoms to cast it. Limited operational range due to losing 1 hp/turn away from her home province.
 * Sea Kings Court W3 Conj-6 You really don't benefit much from this guy, having healthy W picks on all your national magi, although he does generate a W gem each turn, so eventually pays for himself. Sea Troll troops do have their uses, but if you take Turmoil scales, you have a fresh source of mind-controllable free Sea Troll troopers through random events.
 * Telestic Animation S3 Thaum-5 An alternative H2 immobile commander to your Polypal Mothers that won't weigh down your economy with auto-spawn polyp trash.
 * Summon Spectre D3 Conj-6 Uses D gems to notably break into some interesting magic path combos, although you have to get lucky finding enough D gem sites underwater to amass enough gems for casting. Sometimes you can get a E/S pick that will be able to forge Crystal Matrices and Crystal Shields without taking those picks on your pretender. The Kokythiand however offers a more reliable source of strong D magic, so you might prefer to save your limited D-gems for other uses.
 * Streams from Hades W4D1 Conj-6 A guaranteed way to break into Death magic for R'lyeh using it's native W gem income, as you eventually will have a Mind Lord D-random who can cast it. The Kokythiad's potential W/D battle magic synergizes well with R'lyeh's Darkvision-capable troops.
 * Harvester of Sorrows D4 Conj-7
 * King of Elemental Earth E5 Conj-8 E-gem sites are fairly common underwater, so it is likely you will have the gem income to reliably cast this.
 * Queen of Elemental Water W5 Conj-8 The only elemental royalty that must be summoned underwater, so if you control the oceans there is a high likelihood you will be able to get all three uniques.
 * Underwater Troops: All troops able to be summoned underwater are found in the Enchantment or Conjuration schools. Of course, possessing a land-based lab renders this limited selection moot:
 * Enchantment: Reanimation, Claymen, Watcher, Enliven Gargoyle, Enliven Statue, Leviathan.
 * Conjuration: Sea Dogs, Sea Serpent, Shades, Animals, Sea Lions, Kraken, Shade Beasts, Spirit Mastery, Naiad Warriors, Ghosts, Sea Trolls, Asp Turtle, Abomination.

Communions
Don't get fooled into thinking that bringing your Mind Blaster aquatic units onto land is the core of your strategy... that's MA-R'lyeh. Increasing the power of your magi through Communions is the backbone of EA-R'lyeh's threat projection (which btw allows you to bring far more mind-blaster-capable casters onto land than you ever will through forging Amulets of the Fish). There are many ways to set up a communion in Dom3. Let's take a look at a few ways that are useful to EA'R'lyeh:
 * Standard Communion: This is the classic setup where the Masters all come first in the listing order, followed by the communion Slaves. Hence the masters cast, and the slaves are there to soak-up the resulting fatigue. This is the classic way to get multiple casters with 5 or more picks in their respective magic paths for casting the most powerful battlefield spells.
 * Booster Communion: This starts out like a Classic Communion, but with only 1 Master who is armed with a crossbow or wand and each slave scripted to cast Communion Slave then Cast Spells. The Master casts path-boosting spells that will benefit the rest of the communion like Power of the Spheres, Light of the Northern Star, Summon Earth Power, Strength of Gaia, etc but then is scripted to fire closest. Each round in the ensuing battle that the Master fires his crossbow rather than cast a spell (he has 12 ammo, so it should last 24 rounds), the Slaves get to cast spells, but now they cast with the increased benefits from boosted paths! The Booster Communion is very safe for the Slaves: since the Masters stop casting for 24 rounds it is very unlikely any slave will die from over-fatigue. Both the Ethereal Crossbow and the Piercer can be used underwater.
 * Reversed Communion: A reverse of the classic setup, where all the Slaves come first in the order list, followed by the Masters. Scripting is like a Booster Communion. This setup allows both Slaves and Masters to cast each turn, with the slaves benefiting from boosted paths, but is more risky since the slaves will be accruing fatigue twice as fast till they pass out. As long as the battle is over within 12 rounds or so, there are generally no Slave deaths from over-fatigue.
 * Delayed Communion: This can be any of the previously listed communion types, with the difference that the participants first cast up to 4 non-personal-buff spells before they join the communion. An example would be scripting each mage to cast Body Ethereal 3 times, then either Communion Master or Slave. In battle, your entire team of magi will cast Body Ethereal on any nearby squares containing friendly units who are set to Hold and Attack before joining in a communion.
 * Buff Communion: This is a special variation on a Booster Communion, generally requiring more Masters, since each master casts self-buff "personal" spells such as Astral Shield, Personal Regeneration, Invulnerability, etc whose effects are also transferred to the Slaves. You want to load up the Slaves with as many beneficial buffs as you can, hence more masters are needed. Once the masters stop casting, the slaves are free to move up closer to the front line and act as blockers/ or for close-range combat spells.

Ethereality
Body Ethereal (Alt-3 S1) is a spell all EA-R'lyeh's national magi can cast. It makes any affected unit 75% less likely to be hit unless the attacker is using a magic weapon or spell. Not a proper self-buff per se, rather the spell is in fact a short-range AoE spell that affects all troops standing in the target square. Thus there is no guarantee that the caster will target his own square, BUT it is guaranteed that the caster will target a square that is not already ethereal! Your magi can cast Body Ethereal up to 3 times on nearby troops within range set to Hold and Attack before they move. That's a potential per mage of up to 9 size-2 units, or 6 size-3 units, or 3 of any size bigger. There is a pretty good chance that one of those casts the mage will target his own square and any other units sharing it with him. Also, if any other units deployed further to the rear were set to Hold and Attack, your mage might be able to hit their square with additional Body Ethereal casts as they charge past him.
 * Example deployment tactics:
 * 3 Slave Magi in the same square set to cast Body Ethereal 3 times each, with up to 8 "squares" of troops (ie. 8x3=24 size-2 troops, 8x2=16 size-3 troops, etc.) deployed at the same location. The magi will cast BE 9 times in total, thus buffing all 8 squares in range and themselves as well.
 * 1 Slave Mage scripted to cast BE, and a Slave Prince thugged-out with magic equipment in the same square, no other nearby units. The mage will buff himself and the Prince with ethereality.

Obviously this tactic can work well when combined with other buff spells too. Ethereal troops buffed with Quickness or Regeneration can be quite effective.

Mind Control
Your Mind Lords start the game able to cast Enslave Mind in battle to convert an enemy into a mindless friendly thrall under your control. This is a great advantage, but Mind Lords are expensive to both purchase and upkeep, and they only get 5 free casts before they need to be scripted to do something else. With only modest research, Enslave Mind (Thaum-6 S4) offers another way to achieve the same result using your lesser magi. Any mage with S2 can join a reversed communion as a slave (Thaum-2 S1), and the master can buff them to S4 using Power of the Spheres (Conj-3 S1) and Light of the Northern Star (Conj-4 S3). Since 25% of your Slave Magi are S2 and all your Aboleths are minimum S2, this means you can easily form ridiculously huge reversed communions of S4 casters all spamming Enslave Mind. At Thaum-9 you can use a Communion to cast Master Enslave (S8), a battlefield-wide spell that attempts to cast enslave mind on every enemy unit. Make sure to equip the caster with plenty of penetration boosters for maximum effect.

This will be easier to do in provinces with high magic scales, and will be more effective if the caster is equipped with a Rune Smasher, Void Eye and Spell Focus.

Darkness
Most of EA-R;lyeh's national units have Darkvision, which gives these units a huge advantage when fighting in darkness against units that don't have it. Thus it makes sense to prioritize researching the battlefield Darkness spell (Alt-6 D4). Utterdark at (Alt-9 D9) is likely out of reach for all but a dedicated pretender build. While it is technically feasible for a D-random Aboleth or Mind Lord to cast Darkness using a communion, another method is to take enough death on a mobile combat pretender or use the ritual Streams from Hades (Conj-6 W4D1) to summon a Kokythiad and use boosters.

Another research goal would be to use Wish (Alt-9 S9) to summon some Mandehas, one of EA-Lanka's demonic summons who will auto-cast Darkness at the start of each battle. A Mandeha will drown if it is wished for underwater.

Casting Darkness creates a battlefield-wide effect that lasts the whole battle. Undead and blind troops remain unaffected (note: all elementals and many summoned constructs are blind). Units with darkvision have their combat impaired by (100 - darkvision rating) / 2. All other units and commanders have their attack, defense and precision stats halved. This usually is enough to give R'lyeh's national troops a winning advantage. Even so, swarming enemies can still occasionally land hits, so it is best to spam Body Ethereal or other defensive buffs for further protection. Your Slave Mages don't have darkvision, but their spellcasting remains mostly unaffected since the unscripted AI likes to cast Frozen Heart, Mindburn and Soulslay which are all precision-100 spells that always hit their target.

Needles to say combining elemental summons with this spell can also be quite effective. Bottles of Living Water furnish deadly water elemental thugs when fighting under darkness. Regenerating earth elementals are also deadly. Both types of elemental thugs become even better if you cast Body Ethereal on them at the start of battle.

Solar Brilliance
Another battlefield-wide effect that R'lyeh can cast fairly easily. Solar Brilliance (Ench-7 S5) blinds all units on the battlefield and attacks undead/demons. Obviously, units that are naturally blind remain unaffected, thus once again elementals make excellent thugs when fighting under the effects of this spell. It should be pointed out that Polypal Mothers are naturally blind as well. R'lyeh's magi will go blind, but once again the unscripted AI likes to cast Frozen Heart, Mindburn, Soulslay, Mind Control, etc. which always hit their target regardless of whether the caster is blind.

Globals, Globals, Globals
Turtle-up underwater and push research everywhere to leverage your powerful magic asap. Take a pretender that can easily cast high-level global spells. Be aware that 4 of the following can only be cast on land: Since both Maelstrom and the Queens of Elemental Water NEED to be cast underwater, it is likely you will be able to get them as well. But they both require deep research into Evocation and Conjuration, respectively, that brings less synergies with it than Alteration or Enchantment.
 * Enchantment, Gift of Health, Stellar Focus, Earth Blood Deep Well, Haunted Forest, Arcane Nexus.
 * Alteration, Mother Oak, Sea of Ice (empower a Mind Lord), Utterdark and Wish.

Make Claymen once you have a strong E income and move onto land using Communions with your N amphibious mages, dominate in tough fights using Foul Vapours (this tactic doesn't work vs undead nations nor constructs, but against an unprepared opponent it can be quite deadly).

Scale Design
R'lyeh has many troop types that are expensive but light on production. Hence Order or Growth would be nice, with Sloth to pay for it. It's fairly easy for R'lyeh to turtle-up underwater and stabilize positive dominion in its territory using Polypal Mothers and Mer-Priests, thus Growth can pay off in the long haul. R'lyeh's Slave Magi are also mostly old, so high Growth reduces their age by a few extra years. Cold 3 doesn't economically affect underwater provinces and our magi all have water magic to protect themselves from it's detrimental effects in battle. Magic 2 bestows both a research boost and -1 MR in battle, making it easier for our Mind-Blast/Paralysis attacks to succeed.


 * Cash Scales - Sloth 3, Cold 3, Growth or Order 3, Magic 1-2. These scales look towards a stable gold income, while providing a friendly environment for both research and combat casting.
 * Luck Scales - Turmoil 3, Sloth 3, Cold 3, Luck 3, Magic 1-2. Bestows extra design points, but still aims to benefit on average from lucky gem and gold events. You need to be very careful with these scales; not expanding too fast and making sure to quickly preach new territory into positive candles, otherwise a series of unfortunate events can quickly devastate your population or throw your economy into unrest. Take over the seas, then turtle up till research is improved and you have a healthy gem income. We actually like the occasional random Shambler or Sea Troll army invading our provinces, as it gives our Mind Lords a chance to mind-control free tanky units. It also gives us points to take an awake pretender with the high magic picks we need. If you prefer to take the pretender dormant, you can afford some Order/Growth.


 * Balanced - Order 3, Sloth 3, Cold 3, Growth 3, Misfortune 1, Magic 1-3 These are the most expensive scales design-points wise, but they are quite well suited to offer both strong gold income and good growth/research. The effects from misfortune 1 are almost negligible with these scales. There won't be much left over to take an awake pretender.

Pretender Designs
Get A4 on your pretender and Const 6 to forge staff of storms to stop enemy fliers and missile troops. This usually works better for the other R'lyeh ages, since most of your missile troops uses mind blast on land (Mind Blast is 100 accuracy, so not sure if Storm even affects it). But since you lack any kind of Bowmen you might as well stop enemy archers/flyers.

Each pretender offers different strengths according to what globals are wanted:
 * Enchanter of the Void: Void Lurker: E6 S7 D2 N5 B2, Dom 7, use Lucky scales awake or Cash scales dormant. Bless grants +2 MR, +3 Reinvig, 5% regen. Being immobile makes searching for gem sites less efficient till you have the remote spells. Astral allows it to teleport. With the right magic buffs, should make a pretty powerful defensive SC caster, and can even blood hunt a bit on land. Can cast most globals from the Enchantment school without requiring boosters. Only needs a Crystal Coin to be able to cast Arcane Nexus. Easy access to Dwarven Hammer, Blood Stones, Lamia Queens, etc. It's important to realize that with this pretender, you will want to empower a Slave-mage so as to be able to forge Amulets of the Fish (A1W1) or Rune Smashers (F2W2). This presents a fairly large hurdle to get into those items, but at least you can empower a mage with hands to get the Hammer's forge bonus.


 * Master of Utterdark: Master Lich: F2 A1 W2 E3 S2 D8 N4, Dom 6, use Lucky scales awake or Cash scales dormant. Mobile pretender for good researching / site-searching. Death bless can make itself felt if, say, a friendly mage wearing a shroud starts casting remote attacks. Immortality offers some insurance against path-loss if/when our pretender dies from some random snafu. The idea is to Research to Const-4 to pick up useful forging, then go straight up the Alt school to cast Utterdark, which shuts down everyone's gold economy, but our atlantean slave-troops have an advantage. Rainbow paths allows us to forge Amulet of the Fish, Rune Smasher, Dwarven Hammer without needing boosters and hands allows forging hammer bonus. Construction 4 gets us boosters enabling S3 for Crystal Shield, N5 for Mother Oak + Lamia Queens, and D9 for Utterdark. The only Const-4 item on our "nice-to-have" list we can't easily get without empowerment is Blood Stones (B3E2). Since we don't have a guaranteed D gem income, we will have to rely on lucky site-searching and alchemize the rest from pearls to put up a strong global.


 * Lurker of Wishes: Void Lurker: F2 A2 W2 E3 S8 D3 N5 B3, Dom 6, use Cash scales dormant. In many ways similar to the previous pretender, but without mobility. It can remote sight search in any path, and can forge most of the magic items useful to R'lyeh, albeit without a forge bonus. It's strategy is to unlock Const-4 forging, then to bee-line up the Alt school and cast Mother Oak and Wish needing only a Crystal Coin booster to do so. By that time, we should have hundreds of Astral pearls saved up to spend on wishes.


 * Sower of Dark Dreams: Master Lich: E4 S7 D9 N4, Dom 6, use Luck scales imprisoned. This pretender design relies on R'lyeh's national troops and magi to handle early-game expansion and site-searching underwater in exchange for an all-in late-game strong showing in both Death and Astral magic. The Death Weapons bless might be just enough to make your sacred Gibodai troops somewhat more dangerous in battle, as well as granting interesting buffs to anyone else wearing a shroud. Diverse item forging has been sacrificed for a high bless, hence you will need to empower or find another means to be able to forge Amulets of the Fish or Rune Smashers, although much of the useful E/S/D/N items are easily forged at Const-4.

Expansion
Take all underwater provinces and use your N randoms to search for free Kelp Fortresses. Between Voice of Tiamat and your D-random Aboleths, you should be able to find most magic sites underwater. Crank out slave mages for research, you need those E/N random picks for combat communions on land. Don't worry too much about getting onto land till you have the magic and summons to back you up, otherwise you are just going to waste resources and likely get pushed back into the sea by a land power. But even a single land province can offer a place to blood hunt for making Blood Stones and setting up a lab for diverse summons. You can get magic diversification through Naiads/Kokythiads/Spectres (all at Conj-6) underwater and Lamia Queens (also at Conj-6) and Hidden in Sand/ Snow (ench-6) on land.

Research Order
Detour into other schools for low-hanging-fruit battle magic as needed.
 * Alteration to level 3 for Body Ethereal.
 * Conjuration 4 for Voice of Tiamat.
 * Thaumaturgy 1 for Communion Master, Communion Slave.
 * Construction 2 for Dwarven Hammers, Crystal Shields.
 * Alteration 5 for combat buffs, Encase in Ice, Bone Melter and Mother Oak.
 * Construction 4 for Amulets of the Fish, Blood Stones, Crystal Coin, other boosters.
 * Enchantment 5 for Claymen, Foul Vapours, Gift of Health.
 * Enchantment 7 for Stellar Focus, Earth Blood Deep Well.
 * Enchantment 8 for Haunted Forest (if you are in a land war).
 * Enchantment 9 for Arcane Nexus, Gift of Natures Bounty (if you need it).
 * Alteration 9 for Wish.