Ultima weapon is correct, defeat ultimate weapon to get it, you can't sell it or drop it, its power decreases when you get hurt and it has growth:none.
And is the answer Blademaster with mirror image? Uh no thats warcraft...
It's not one of those dodgy flashbacks where Cloud is beside himself is it? Or not necessarily a flashback but just an illusion/mental breakdown/schitzophrenia thing...
