Agreeing with you on Vergil and Kagura.Vergil and Kagura from Fairy Tail.
Dante and.... Gintoki?
Nero and Morrigan .----------.
Could be Morrigan Aensland from Darkstalkers. I hear they kinda flirt with one another in U/MvC3.As in Morrigan from dragon age? hehe I'd love to see this; she would eat the poor kid alive.
Makes sense too, because DmC's opening had strippers dressed up with angel wings. Panty and Stocking (who then became a demon) are angels who do erotic poledancing.
Vergil and Kagura from Fairy Tail.
Dante and.... Gintoki?