Dante is NOTHING like Sephiroth. Sephiroth is evil and has a style completely different than Dante. “Oh they have a sword and white hair.” Guess what Dante has. A sword, transforming nunchucks, a motorcycle sword, wind and fire dual blades, summon swords, fire gauntlets and greaves, metal wings that stick thorns into you that explode when a rose is thrown at them, and an electric guitar that shoots bats. Let’s not forget his dual pistols, shot gun, dual rocket launchers, magic hat, and magic brief case that can shift between 666 different forms! Dante is also a fun loving guy with a lot of personality and he loves to play with his enemies! He’s also got TWO different forms!
TL;DR Dante is VERY different than Sephiroth if you more than glance at him.