>_< Gotta make me choose between my two favourite game characters haven't you. :lol:
Well, both are skilled swordsmen, but I think Vergil would come out on top, his Devil Trigger gives him a HUGE advantage, along with the fact that he gets regenerative powers along with it, whereas Sephiroth pretty much relys on strength alone.
Vergil has speed and power going for him, whereas Sephiroth has a 6 foot Katana and some sweet moves, Vergil's certainly got the upper hand, I think if the two were to go toe to toe, it'd be close though, Sephiroth could match Vergil blow for blow if he really tried, his strength could be said to overpower Vergil.
But like I said, Vergil has that one feature that clinches it for him, Devil Trigger, the second Vegil goes DT, Sephy gets pounded into the ground.