Well, as shown in Batman vs superman, if an athletic human can get some kryptonite gloves/blades, then they win.
But if thier is no kryptonite, sephy loses
always!
Please. Super-man could take every FF character that ever existed, and the summon mosnters, too.
Sephiroth is a god, Super-man is an alien.
Is there Kryptonite in Midgar? If so...Sephiroth.
If there is no Kryptonite, Sephiroth would lose.