Excalibur
Excalibur is supposed to be a powerful weapon for Cloud. To get Excalibur, you must fill the slots of Cloud's Ultimate Weapon with mastered KoR materia. Cloud's Ultimate Weapon will then turn into Excalibur, the most powerful weapon in the game.
Masamune Blade
You can also supposedly get the Masamune Blade, Sephiroth's weapon. To get this weapon, you must get Sephiroth to join your party. Apparently it is possible for Cloud and Sephiroth to swap weapons as they both use swords.[OR]- It has also been rumored you can get the Masamune Blade by winning 99 Masamune Blade copies at the Golden Saucer's rollercoaster and giving it to the Weaponmaker who wants Mythril. He'll meld the copies into a proper Masamune Blade for Cloud to use in exchange for Mythril.
