If I could change anything in FFVIII... I'd make Ultima Weapon a whole lot stronger.

Kinda like this:

HP: 15,000,000
Str: 255
Vit: 255
Mag: 255
Spr: 200
Spd: 255
Hit: 255
Evade: 50
Luck: 100

Auto-Haste, Auto-Protect, Counter.

Immune to all status-effects. Immune to The End.

Attacks:

Megido Flame
Terra Break
Ultima
Terra Break
Bad Breath
Light Pillar

All used randomly... etc