Each character has an Ultimate weapon here is
were you find them all
Cloud will receive his Ultimate weapon once you
defeat the monster Ultimate WEAPON. This monster
is found hovering over the lake on the eastern
Barret will get his ultimate weapon on the steps
leading to Hojo in Midgar. Keep in mind that you
need him in your party in order to see the box
containing the weapon in the first place.
After getting the "Key to Sector 5",
you can return to Wall Market and check the broken
vending machine again. It's fixed and gives you
Tifa's final weapon.
You can get this in the temple of ancients. Just
off the clock room at the end of hallway IV.
XIII- After taking Bugenhagen to the Ancient city,
return to Cosmo Canyon with RedXIII in your party.
Bugenhagen gives Red XIII his ultimate weapon.
Sith- During the team's second raid on Shinra
HQ you can find Cait Sith's ultimate weapon from
a lock on the 64th floor. The locker is on the
left side 3rd row down.
Once you get the sub, locate the crashed shinra
plane off the coast of gold saucer. Yuffie's weapon
is inside the generator room.
At rocket town there is an old man staring at
the rocket. Talk to him and keep talking until
he gives you Cid's ultimate weapon.
Go to lucrecia's cave during disk 3 to get Vincent's