Anime Character's Evil Counterpart/Evil Twin: Discussion

[Star_Of_Hope]

Like Diva from Blood+
She is the evil twin of Saya but she was made to turn out that way when her parents gave everything to Saya. Are there any other such characters?

 

[Blackangel]

i really can't remember any character like that star
and there are too many sub characters like evil ichigo or evil rukia or their swords episodes