Castlevania: Curse of Darkness/Innocent Devils

Innocent Devils (IDs) are demon servants brought to life by Devil Forgemasters. IDs are computer controlled allies that assist Hector in different ways. Most can fight along side him and learn spells that cause damage to enemies, heal/cause status aliments, heal Hector, and some have special uses. All IDs give bonuses to Hector's stats when summoned, however what stats are improved depends on the ID. Each type of ID has numerous forms that it can grow into. There are four levels of growth, and at each of the first three levels the ID has one or two possible forms it can evolve into. Each form will learn an additional 1 to 3 attacks.

IDs grow in several different ways.
 * Levels — IDs gain levels by collection experience points, just like Hector. ID stats will improve as its level increases, as will the stat bonuses given to Hector.
 * Skills — Each form of an ID learns between 1 and 4 skills, and level 1 forms come with innate skills. Most of the higher level skills are granted after a certain number of enemies have been defeated by Hector or the ID while in that form. Some skills are learned in other ways, and once an ID moves past a form it cannot learn skills it missed.
 * Form — What form an ID is determines what skill it will learn, how aggressive it is, it's style of attack, and other functions. Forms change when a set number of evo crystals have been collected (crystals are randomly dropped by enemies). There are five types of crystal — one for each type of weapon, and what types of crystals are collected determine what for the ID will evolve into next. Tier 2 forms require 40 crystals, tier 3 forms require 70 crystals, and tier 4 forms require 90 crystals, which may seem like a lot, however there are quite a few enemies that drop crystals frequently.

There are six types of IDs:
 * Fairy Healers that can restore both life and status
 * Battle Brawlers that can fight as well as you
 * Bird Fliers with devastating skills
 * Mage Magicians with powerful offensive and defensive spells
 * Devil Use the Magic Circle to move anywhere
 * Pumpkin An optional ID that provides massive stat bonuses when summoned

Each form has three settings:
 * Automatic: the ID will automatically use any skill it has when it wants. The exception is the Devil type, which never uses its skills without being commanded.
 * Command: You tell it to use specific skills with the Triangle button. There are several skills that Fairies can use without being commanded to do so even in Command mode.
 * Guard: The ID will not attack and will attempt to block all enemies. Not all attacks are blockable — if Hector cannot block it, the ID cannot block it. Fairies do not have a guard mode, but they do not take damage in Automatic or Command modes.

Fairy
Fairies focus primarily on healing, but can also fix various status ailments and grant invulnerability. There are a handful of offensive skills, mostly used by the Comet Star, but they aren't that great. It's usually better to focus you efforts on learning healing skills and use battle or bird IDs for fighting. They have relatively low hearts, but since they cannot be hit by enemies, you can use it all for healing.

Recommended path:
 * Infant Fairy → Leaffle → Killer Bee → Tiramisu
 * Actually, it's more important that you get the Leaffle and Killer Bee skill sets than the Tiramisu's, however it's skills are a bit more useful than the Tiara's. Heal Lvl. 3 will restore the most HP per use of any level, except Gold Heal. Time Heal restores a moderate amount of HP over an extended period, but is dirt cheap. Use it after each screen to refill your HP and you'll stand a much better chance of surviving. Poison Powder is useless in terms of damage, but tends to disrupt the enemies' attacks.

Required Skills:
 * Unlock — Infant Fairy (opens treasure chests)
 * Press It and See — Proboscis Fairy (presses a button that Hector cannot reach in the Castlevania: Curse of Darkness/Areas#Aiolon Ruins|Aiolon Ruins]])
 * You will need a Proboscis Fairy to get to every place in the game, but it should not be your main fairy. It is the combat fairy, though it is nowhere near as powerful as some of the other types, and you sacrifice most of the good healing skills by going that route. Build one up and then just keep it in storage until you need it.

Battle
Battle types are, as can be expected, your main fighters. Aside from simply beating the crap out of anything and everything, they can create a defensive field that will protect you (though the ID cannot attack or even move while generating it). While they have a number of incredibly powerful skills, you can generally just let the ID fight with it's weapon, which will defeat the enemies just as quickly and save you hearts. They have very high hearts, but since they loose hearts when hit, you'll want to use them as life points rather than skill points.

They fight well, but tend to take a lot of damage as well since they dive into the middle of the battle. This is fine in most cases since you'll get a steady stream of hearts that heal them, but they tend to get beat up during boss fights. They have no defensive tactics, so they do nothing to get out of the way of the boss's power attacks and you can't get more hearts during the fight.

Recommended paths: (note that these paths do not have a level 3 form)
 * Magmard → Speed-Mail → Corpsey
 * Magmard → Speed-Mail → Rasetz
 * Both are insanely powerful and fast (Corpsey is slightly more powerful, Rasetz is slightly faster) to the point where you don't even need to participate in some fights. Really the only deciding factor is whether you want a ghost samurai or a gigantic sword-wielding demon on your side.

Required Skills:
 * Brute Force — All forms (opens iron doors)
 * Brute Force Lv. 2 — Juggernaut (opens an iron door in the Infinite Corridor)
 * Hip Press — Golem (breaks a weak floor in the Forest of Jigramunt)
 * Shoulder Ride — Iytei (crashes through a barricade in the Forest of Jigramunt)
 * You'll notice how the required skills from forms not on the recommended path. Perhaps this was Konami's way of trying to force you to get everything. Oh well, both the Iytei and Juggernaut forms are powerful, so it's not a complete waste of time.

Bird
Birds are fantastic IDs — aside from being necessary to cross gaps, they are very strong (though not nearly as strong as the Battle types). They are also significantly faster, and since they are airborne they take much less damage than the Battle types. Many of their skills target wide areas, so they are perfect for hitting large groups. Their main attack (a dive bomb) is weak, but they can attack repeatedly for massive damage and can disrupt enemy attack.

Recommended paths:
 * Crow → Skull Wing → Wingosaurus → Indigo
 * Crow → Skull Wing → Wingosaurus → Crimson
 * The other three final forms are fairly useless, especially compared to these two. They are fast, powerful, have numerous strong skills. They are basically the same — the only difference is that Crimson has fire based attacks and Indigo has ice based attacks. Eventually you should get both since fire and ice are the two most common weaknesses among the enemies.

Required Skills:
 * Glide — Crow (cross gaps)
 * Long Glide — Wingosaurus (cross longer gaps)
 * You'll need Glide to get from the Mortvia Aqueduct to the Forest of Jigramunt, as well as a bunch of treasures in other areas. Long Glide is needed to get to several optional areas, including the Tower of Evermore.

Mage
Mage types have similar traits to the typical wizard classes found in RPGs — powerful skills/magic (offensive and defensive), but low physical attack and life, and near non-existent defense. This means you have to be somewhat conservative about using their skills since it takes away their life points when they use them. Properly used, Mage IDs can be more devastating than Battle IDs. A Mage skill also can kill the red skeletons, which keep resurrecting when you hit them with normal weapons.

Required Skills:
 * Time Stop — Wood Rod (stops time, surprisingly enough)
 * Purify — Nautilus Rod (kills red skeletons)
 * Both skills are needed to access a few areas in the game, and Purify not only opens new areas but finally lets you kill those damn red skeletons. If you've ever played Castlevania III: Dracula's Curse you'll love this opportunity. Any time a door or path closes to quickly to get through, you probably need to use Time Stop.

Devil
Devil IDs are as important surviving the enemies as they are for advancing the storyline. It also only has three forms, and getting to the last one requires building a rather complex weapon first. It's skills aren't particularly interesting, though necessary to access various areas. Its final skill, Explosion Magic Circle is quite powerful if used properly. The true greatness of the Devil ID comes from its physical attacks. As fast as a Bird ID and as powerful as a Battle ID Against many enemies a Devil can do more damage per swing than Hector, though it does not attack as rapidly. It is also extremely aggressive, unlike the Bird type, which sometimes just flies around not fighting anything.

Recommended path:
 * Gale → Brow → The End
 * Actually, it's the only path.

Required Skills:
 * Magic Circle — Gale (slide through narrow gaps)
 * Basically the only useful Devil ID skill, and it's an inherent skill. Get, level up a lot, and then go fight Legion. Getting the final skill is time consuming, so only do it if you are a completionist or really bored.

Pumpkin
An optional ID, Pumpkin was a bonus character you could play as in Castlevania: Lament of Innocence. You can also use him in Castlevania: Curse of Darkness with the same abilities. He does not attack or heal, but gives large bonuses to your stats, so this is a good ID to equip if only Hector is fighting. It has several forms, and they all branch off of the initial form or are the only option after level 2. The forms are merely cosmetic as the stat bonuses do not change and Pumpkins never learn any skills. However, it does allow you to carry another ID in your deck just by getting it, so it's not quite completely useless.

Recommended path:
 * None
 * The differences between forms is only cosmetic, so you can just stick with the base form unless you want more to do.

Required Skills:
 * None
 * Pumpkins do not have skills.