The Final Battle

Deathguise always opens with Meteor, so enter the fight with the party fully restored rather than planning to set up first. Its closed form leans on Death, LV5 Death, Twister, and Meteor; its open form switches to stronger direct attacks. The major exploit is Sleep: Deathguise is vulnerable to it despite being part of the final sequence. Put it to sleep, then use magic and other non-waking damage sources while refreshing Sleep before it gets a turn. Slow is also effective. Check levels for multiples of 5 before the battle, and lean on Ice or Wind when attacking normally. Winning cleanly matters because the final sequence continues immediately afterward.

Grand Cross is the entire fight. It can apply a huge collection of status ailments at once and can also leave characters at single-digit HP; Necron then follows with Neutron Ring, so recovery must be queued before the second hit arrives. Load the party with status immunities such as Body Temp, Jelly, Clear Headed, Locomotion, Antibody, Insomniac, and Loudmouth according to available Magic Stones. Zombie is the exception to ordinary Remedy cleanup: use a Magic Tag on a zombified party member before relying on Angel's Snack or healing. Quina's Angel's Snack is one of the best responses to Grand Cross, while Mighty Guard and Auto-Life give the party enough margin to survive bad status rolls. Slow works on Necron, and Wind or Holy provides an elemental edge. Keep one fast character ready to recover the group rather than committing every ATB bar to offense at once.

Do not enter this fight under Reflect and do not deliberately drain Trance Kuja to 0 MP. Both conditions encourage Flare Star, whose damage scales directly with each character's level and can become more dangerous than his normal spell cycle. Slow works and is worth landing early; Shell is far more useful than Protect because Kuja's offense is overwhelmingly magical. If he Reflects himself, Dispel it or use non-reflectable abilities rather than bouncing spells around. A strong exploit is Auto-Regen combined with long summon animations: while an Eidolon such as Ark plays out, Regen continues ticking and can restore much of the party before the next action. At the end Kuja casts Ultima as a scripted transition, so do not waste resources trying to prevent that final event.