Sorry to differ but I think she's the weakest character in terms of personality, weapons, moves etc.
She's a bona fide case of a good idea gone disasterously wrong.
Her throwing daggers don't make for too much a different projectile from Dante's guns, gameplay wise. Her swords have all of the flaws of DMC2s weapons: Lack of personality, negligable difference upon upgrade, you get the idea.
I also find her extremely annoying, obviously fake accent a real ****er to cope with as well.
Sorry but I'm fairly opinionated.