Instructions
Adrammelech (Level 40+)
Cast Shell on your party to reduce the magic damage done by Adrammelech and the Shambling Corpses he summons to his aid.
Cast Telekinesis, 1000 Needles or any Ice elemental spell to attack Adrammelech. He uses Perfect Defense, which temporarily negates all damage, once he starts to get near death.
Kill the Shambling Corpses until Perfect Defense wears off.
Attack Adrammelech after Perfect Defense wears off to kill him.
Zalera (Level 40+)
Enter the battle against Zalera with your characters at a level that is not a prime number, divisible by three or divisible by four. If possible, it should also not be divisible by two or five. Zalera has several attacks that only hit characters at a specific level. Prime Level Death, Level 3 Disable and Level 4 Break are the most dangerous unless you are immune to those specific status effects. Level 2 Sleep and Level 5 Reverse are annoying but far less devastating.
Kill the Dead Bones that Zalera summons.
Cast Arise or use a Phoenix Down immediately after Zalera kills any party member. He uses a large number of instant-death attacks. You want to avoid having party members lying around dead for any extended period of time. Zalera can quickly overwhelm you with death attacks if you get unlucky and don't keep every party member active.
Attack Zalera with normal attacks and healing spells. Zalera is immune to all eight elements. Zalera is undead, so healing spells damage him.
Cuchulainn (Level 45+)
Equip Black Belts before fighting Cuchulainn to prevent Disable.
Cast Bubble to increase the health of your party members. Your health constantly drains when fighting Cuchulainn, making this bonus health valuable.
Kill the Foobars Cuchulainn summons to help him.
Attack Cuchulainn. He has no weaknesses to exploit, so just use whatever your most powerful attacks are for your party members.
Exodus (Level 45+)
Cast Shell on your party to reduce the amount of magic damage Exodus can do.
Attack Exodus with normal attacks. He uses Paling, which negates physical damage, when he is getting close to dying.
Cast Dispel to remove Paling.
Attack Exodus again to kill him.
Zeromus (Level 50+)
Attack Zeromus with normal attacks. Due to the anti-magic field, you cannot use spells during this battle.
Use Hi-Potions and X-Potions to keep the health of your party up.
Use your Quickening attacks whenever your MP (Magic Points) is full. There is no reason to conserve MP because you cannot use spells. Zeromus should not pose too much of an issue after he is hit by a few Quickening attacks.
Chaos (Level 65+)
Equip your characters with any accessories you have that reduce wind damage. Chaos' only really major damage attacks are wind based.
Use Esuna immediately after Chaos uses Aeroja on any character with the confused status effect.
Attack Chaos with Telekinesis, Souleater, non-elemental spells or earth elemental spells. All of these are effective against him. As long as you avoid letting your party members get confused, this fight is solely a matter of wearing down his health.
Ultima (Level 65+)
Equip White Masks on all of your characters. This accessory causes holy damage to heal your characters. This negates the main threat of almost every major attack Ultima possesses.
Dispel the reverse status effect on your characters after Ultima uses Redemption. Reverse causes healing spells to cause damage. If you leave Reverse up, Ultima starts to cast healing spells on that character, quickly killing him.
Cast Darkga or Dark Shot or attack with ninja swords to do additional damage to Ultima; otherwise, use normal attacks. Ultima is immune or resistant to everything else. As Ultima's health drops, you lose access to most of your abilities. Use whatever you have available. Ultima should already be close to death before this is an issue.
Zodiark (Level 80+)
Equip Black Masks. This accessory causes dark damage to heal your party members. Most of Zodiark's attacks are dark damage based.
Enter the battle with your characters at a level not divisible by two, three or four. This eliminates the risk of Zodiark's Level 2 Sleep, Level 3 Disable and Level 4 Break spells.
Attack Zodiark with normal attacks until he uses Paling. He uses Paling once his health becomes critically low.
Attack Zodiark with non-elemental spells after he uses Paling.