I like it!
I'm not really into dramatic stuff, but that's pretty good. But, a couple things:
A) Sephiroth's sword is the Masamune, not Murasamune. But whatever.
B) If Vincent and Sephiroth were to team up, you'd need like everyone else from FF to take 'em down. Definitely need Squall.
C) Yay, Nanaki!