Crossbone Isle is an optional and secret dungeon-style location in Golden Sun and is easily viewable as that game's primary "super-dungeon", much like how many Role-Playing Games feature one or more dungeons more challenging than the normal "final dungeon" that game features. It is filled with powerful and unique enemies and equipment within its ordered series of ten floors of puzzles, and is most notable for having the most powerful monster in the game that aspiring players can fight, Deadbeard.
Getting there
There are two ways to reach Crossbone Isle. The first way to get there is by event on the Tolbi Bound Ship. You must select passengers in a certain order in order to get there. If you want to get there via this method, you wouldn't get very far due to your party members lacking certain psyenergy to bypass certain areas. The other way to enter Crossbone Isle is riding the pinkish Tornado in Suhalla Desert. The Pink Tornado is reachable by entering the cave behind Flash, the Mars Djinni. To those who do not know how to reach the djinni, enter the second map in Suhalla Desert and travel on until you come across a area where you climb down into the desert sand (right before fighting the Storm Lizard boss). DO NOT climb down, instead head left and use reveal to reveal a hidden log and some shining footprints. Follow the footprints and you'll find Flash. Enter the cave before you and follow the path to find the Pink Tornado, enter it but do not use douse, instead let it carry you and you'll be transported to the world map on a remote island. If you do happen to use Douse on the pink Tornado, you'll end up fighting the Tempest Lizard.
Tempest Lizard (Optional) HP: 3000 PP: 45
Weak to: Venus Resistant to: Jupiter
Abilities: Attack: This is this monster's standard physical attack.
Wing Stroke: A Monster Skill that shoots out wide sets of massive glowing yellow feathers through multiple Adepts dealing a Jupiter-based attack with a range of 3.
Sonic Slash: A 3rd level Psynergy spell that projects huge glowing swaths of energy through the party of Adepts, dealing a Jupiter-based attack with a range of 5.
Storm Ray: A 2nd level Psynergy spell from the 'Ray' series.
Tempest: A 3rd level Psynergy spell from the 'Whirlwind' series. It summons four large, electrically charged tornadoes to cycle through the positions of the party of Adepts. It is by far the strongest attack from the Tempest Lizard.
Impact: A Psynergy spell that buffs up 1 target on the user's side of the field by increasing the target's current Attack rating by 25%.
Ward: A Psynergy spell that buffs up 1 target on the user's side of the field by increasing each of the target's Elemental Resistances by 40.
EXP: 1360 Money Gained: 6400 Drops: Potion
So kill or ignore Tempest Lizard if you want here, if you do happen to kill it though, the tornado will disappear and you'll be trapped on the island FOREVER!!! Just Kidding. To make the tornado reappear, enter the centre of the island and exit back to the world map and it'd be back.
Crossbone Isle
Outside
Now, to begin with, the dungeon entrance is located on the centre of the island, enter there and there should be a cliff. Use 'Growth' (get this by giving a mars djinni to Isaac or a Venus Djinni to Garet) on the vines. Ignore the nearby whilwindable bushes and continue climbing up. At the top there should be a tree with a Nut acquirable with catch and three slides, the one on the far right will take you to a chest containing a mint, the centre will take you to a chest with 1 coin and the one on the far left will take you to the enclosed ground with a bush. Use whirlwind and the entrance to Crossbone Isle is revealed.
Basement 1
When you enter, go downstairs and there you should arrive at a floor where there's a big gap and a pillar on the other side. Ignore that for now and prepare yourself for a battle before entering the door:
Monsters: Hobgoblin x1 Virago x2
Hobgoblin
HP: 650
PP: 0
Weak to: Jupiter Resistant to: Venus
Abilities: Attack: The Hobgoblin can only use the attacking skill.
Aside from it's offensive attack, it has items: 1 Crystal Powder: An item that generates a 'Hail Prism' psyenergy that deals moderate Mercury damage. 2 Nuts: Heals 200 HP 1 Sleep Bomb: A chance that one Adept will be inflicted by the Sleep Status 1 Smoke Bomb: A chance that one Adept will be inflicted by the Delusion Status
EXP: 223 Money Gained: 800 Drops: Lucky Medal (guaranteed)
Virago
HP: 185
PP: 0
Weak to: Jupiter Resistant to: Venus
Abilities: Attack: The normal attacking skill.
Banshee Howl: A Monster Skill that launches rings of purple energy through a targeted Adept, dealing a Jupiter-based attack and a chance that the hit Adept will be inflicted with Stun.
EXP: 87 Money Gained: 120 Drops: Elixir
When you defeat the 'miniboss' enter the room and you'll discover a 'jumping' puzzle.
The room is mainly focused on using the 'Move' Psyenergy and creating your own path through this jump puzzle. Furthermore, there are several chest littered throughtout this map.
If you want to reset the pillars positions, simply exit and reenter the room. Most of the items here are worthless except for a chest containing the Hard Nut and the potion (which the chest is a Mimic).
Once you exit the room via the left door, push the pillar on your right and head downstairs on the left.
Basement 2
Once you head down, the outside room is designed in a similar fashion to the previous one, however the door guards are different. Prepare yourself and enter the door to start the fight.
Monsters: Grisly x2 Succubus x1
Grisly
HP: 800
PP: 0
Weak to: Mars Resistant to: Jupiter
Abilities: Attack: The normal attacking skill.
Bear Claw: A Monster Skill where the monster charges towards a targeted Adept and unleashes 5 red glowing claw swipes in rapid, brutal succession.
Berserk: A Monster Skill has the battle text read "Grisly erupts in a furious rage!" as the monster surrounds itself in a small fiery energy. This boosts the user's Attack by 25%, which for the Grisly means 52 attack points.
EXP: 243 Money Gained: 700 Drops: 1 Potion from both Grislys (guaranteed)
Succubus
HP: 529
PP: 56
Weak to: Mars Resistant to: Mercury
Abilities: Attack: The normal attacking skill.
Hail Prism: A level 2 Psyenergy skill from the 'Prism' series, deals moderate Mercury damage.
Wind Slash: A level 2 Psyenergy skill from the 'Slash' series, deals moderate Jupiter damage.
Heartrender: A Monster Skill has the battle text read "Succubus glowers miserably at you” as a group of glowing pinkish-white hearts converges on a single target, lowering their attack power by 25%.
EXP: 101 Money Gained: 143 Drops: Crystal Powder
This room requires no psyenergy, it does however involve a rolling pillar puzzle. There are 4 chests, one containing Lucky Pepper, 222 coins, Elixir and Mystery Blade, a light blade that gives 84 attack and unleashes Life Nourish.
To bypass this room, push the rolling pillar to the left of the upper right chest left, then go to the center right chest and push up the rolling pillar near it. Then go to the bottom chest, push up the rolling pillar behind that, then go around to the rolling pillar just above that chest to the left and push it right. The upper-left-most pillar can now be rolled up, and after getting the Mystery Blade from the last chest, exit the room off the bottom left.
As of the last floor, push the pillar on the right and head left downstairs.
Basement 3
Once again, prepare for the upcoming battle and enter the door to fight the door guards.
Monsters: Lich x1 Fiendish Ghouls x2
Lich HP: 900 PP: 52
Weak to: Jupiter Resistant to: Mercury
Abilities: Attack: The normal attacking skill.
Glacier: A level 3 Psyenergy skill from the 'Frost' series, deals moderate high Mercury damage.
Revive: Revives a felled ally, in this case if either of the Fiendish ghouls are downed, it can be revived.
Curse: A Psynergy spell that briefly generates a candle icon at the target Adept's position, and the target has a chance to get inflicted with a 7-turn Death Curse status ailment. Being used a "boss"-style encounter that technically lasts more turns than a normal battle, this ability just might end up downing an Adept if cast first thing in the battle and the battle lasts over 7 turns.
Enfeeble: Psynergy spell that targets up to 3 Adepts, for each one attempting to temporarily lower all of that Adept's Resistances by 20 points, increasing the damage the party takes from any attack involving an element.
Haunt: A Psynergy spell that causes a mass of purple skull symbols to swirl into each party member, and each affected party member has a chance to get inflicted with the Haunt status ailment.
Debilitate: a Psynergy spell that targets up to 3 Adepts, for each one attempting to temporarily lower that Adept's current Defense rating by 12.5%.
Bind: A Psynergy spell that displays a holographic symbol onto a targeted Adept, attempting to Seal that Adept's Psynergy capabilities.
EXP: 263 Money Gained: 1200 Drops: Psy Crystal (guaranteed)
Fiendish Ghoul
HP: 609
PP: 0
Weak to: Mars Resistant to: Mercury
Abilities: Attack: The normal attacking skill.
Cannibal Fang: A Monster Skill where a glowing orange holographic image of a pair of jaws chomps at the position of a targeted Adept three times while energy is siphoned into the monster, dealing a Venus-based attack that siphons around 24 HP from the target to the user.
Bacteria Rush: A Monster Skill where the monster bolts forward and deals seven brutal glowing green claw swipes in a row against a targeted Adept, dealing a Venus-based attack equal to its normal physical attack with an additional 16 damage points, and the struck Adept has a chance to get inflicted with Poison.
EXP: 87 Money Gained: 109 Drops: Antidote
This room is similar to the one on the 1st floor basement except the psyenergys Reveal and Catch are needed instead of Move.
4 Blue Keys and 1 hidden Red Key is littered in the room on square pillars, the only way to retrieve them is by using the Psyenergy 'Catch'.
The Blue Keys can be used to open the blue doors on the top of the room with chests containing from left to right: 333 coins, the Fairy Ring, a Cookie, and a Smoke Bomb. The Fairy Ring acts like an Elixir in battle.
To find the red key, hop onto the pillar below the chest containing the smoke bomb and cast Reveal to reveal a platform with a red key in the middle of the pillar circle, use ctach to retrieve the key and head left to open the red door on the left side of the room.
Exit this room via the right and move the pillar on the right side and head downstairs.
Basement 4
Again, prepare yourself and head towards the door for the upcoming battle.
Monsters: Gryphons x2
Gryphon
HP: 1100
PP: 36
Weak to: Jupiter Resistant to: Venus
Abilities: Attack: The normal attacking skill.
Wing Flutter: A Monster Skill that shoots out small sets of sharp glowing yellow plumage through multiple Adepts dealing Jupiter based damage.
Twin Beaks: Monster Skill has the monster shooting 2 purple projectiles at a targeted Adept, dealing a Jupiter-based attack equal to the user's normal attack with an additional 30 damage points, and there is a chance that the resulting damage will be doubled.
Sonic Slash: A 3rd level Psynergy spell that projects huge glowing swaths of energy through the party of Adepts, dealing a Jupiter-based attack with a range of 5.
Tornado: A 2nd level Psynergy spell from the 'Whirlwind' series. It summons two large, electrically charged tornadoes to cycle through the positions of the party of Adepts.
Impact: A Psynergy spell that buffs up 1 target on the user's side of the field by increasing the target's current Attack rating by 25%.
Bind: A Psynergy spell that displays a holographic symbol onto a targeted Adept, attempting to Seal that Adept's Psynergy capabilities.
Ward: A Psynergy spell that buffs up 1 target on the user's side of the field by increasing each of the target's Elemental Resistances by 40.
EXP: 303 Money Gained: 1900 Drops: Potion (guaranteed)
After defeating the Gryphons, you'll enter into a dark room. To those who arrived by the Tolbi Bound ship, I'm afraid that this is the furthest you can go as you are lacking the Cloak Psyenergy (unless you somehow hacked the Cloak Ball of course), however if you do have 'Halt' you can reach 1 chest containing a measly Sleep Bomb.
If you do happen to have the Cloak psyenergy, you can bypass the statue in the darkness, simply stay in the shadows and sneak past the statue. However if you do happen to come across a statue in the lighted area (where you cannot cloak), use 'Halt' on it and it will freeze allowing you to bypass it.
There are 4 chests in the room containing a Sleep bomb, Smoke bomb, a Psy Crystal and a Storm Gear. The chest containing the Storm Gear is on the top right corner of the map.
Once you've done with this room, exit via the right, push the pillar on the right once again and head down another floor.
Basement 5
Once again, prepare yourself and head towards the door for the upcoming battle.
Monsters: Lizard King x1 Harridan x1 Stone Soldiers x2
Lizard King
HP: 2000
PP: 52
Weak to: Mars Resistant to: Mercury
Abilities: Attack: The normal attacking skill.
Ice Blessing/Breath: A Monster Skill that has the monster generating a mass of air filled with pieces of ice at the party of Adepts dealing a Mercury-based damage. Essentially this monster's main form of attack.
Debilitate: A Psynergy spell that targets up to 3 Adepts, for each one attempting to temporarily lower that Adept's current Defense rating by 12.5%.
High Impact: A Psynergy spell that buffs up each monster on the user's side of the field, including itself, for each one raising its current Attack rating by 12.5%.
Hail Prism: A level 2 Psyenergy skill from the 'Prism' series, deals moderate Mercury damage.
Blunt: A Psynergy spell that targets up to 3 Adepts, for each one attempting to temporarily lower that Adept's current Attack rating by 12.5%.
Ward: A Psynergy spell that buffs up 1 target on the user's side of the field by increasing each of the target's Elemental Resistances by 40.
EXP: 535 Money Gained: 1200 Drops: Psy Crystal (guaranteed)
Harridan
HP: 231
PP: 29
Weak to: Jupiter Resistant to: Venus
Abilities: Attack: The normal attacking skill.
Banshee Howl: A Monster Skill that launches rings of purple energy through a targeted Adept, dealing a Jupiter-based attack and a chance that the hit Adept will be inflicted with Stun.
Wind Slash: A level 2 Psyenergy skill from the 'Slash' series, deals moderate Jupiter damage.
Crazy Voice: A Monster Skill that generates a batch of small glowing purple musical note symbols that floats into a targeted Adept and shatter, lowering the Adept's PP meter by roughly 10 points.
EXP: 150 Money Gained: 164 Drops: Nut
Stone Soldier
HP: 179
PP: 6
Weak to: Mercury Resistant to: Mars
Abilities: Attack: The normal attacking skill.
Headbutt: A Monster Skill where the monster charges forward shrouded in glowing red aura and rams a targeted Adept, dealing a Venus-based attack equal to its normal physical attack with an additional 60 damage points.
Blast: A low level Psynergy spell from the 'Blast' series that creates a small explosion dealing Mars-based damage.
Mad Blast: A low-mid level Psynergy spell from the 'Blast' series that creates a medium sized explosion dealing Mars-based damage. However since this skill costs 9 PP, the Stone Soldier could never use this skill against you, but this won’t stop the Stone Soldier from attempting to cast it in vain...
Dynamite: A Monster Skill where the monster leaps forward into the party and disappears in a massive explosion, dealing heavy Venus-based damage. This attack removes the user from the battle in a way that it is not counted as "felled" (you don't get its EXP and coins).
EXP: 98 Money Gained: 98 Drops: Elixir
Once you've taken care of the guardians, you'll find yourself in a room similar to the Kolima Forests Floodgate Puzzle.
There are 4 chests in this room each containing 555 coins, a Potion, a Lucky Medal and a Ninja Garb, a moderately defensive armor with a huge agility boost and some Jupiter resistance. The chest containing the Ninja Garb is located in a spot enclosed by rocks.
Getting the Ninja Garb: There are six logs in the area, but two of them are permanently fastened in place, so only the four logs between them are to be moved. There are essentially two horizontal logs rollable up-and-down and two vertical logs rollable left-and-right. First, head counter-clockwise around the room's perimeter to a chest with 555 coins. Then go down to where the rolling logs are. To get to the lower left-most chest, roll the lower vertocal log left, then roll the left horizonal log down, then the right horizontal log down, then the lower horizontal log right, and finally the right horizontal log back up, creating an effective path to one particular chest that will be traversable once the floodgate switch at the elevated bottom of the room is flipped. The chest contains the Ninja Garb.
Once you're done here, exit this room and once again, push the pillar on your right and head down.
Basement 6
(To be continued)