Just drop any ideas here that you feel would make a Castlevania fighting game worth buying, playing, and treasuring.
Here's some of my ideas:
1.) Make the characters LOOK LIKE THEMSELVES (obviously).
2.) Make the game deliberately non-canon, rather than make us sit through another round of "IZ JUJMEANT KANON?" fights that figure so prominently into my memory.
3.) More characters from more games. I remember seeing the cast for Judgment and going "Seriously? THAT'S IT?"
4.) Incorporate some guest characters whose presence could be logically justified in a Castlevania setting, like Dante from Devil May Cry winding up in Castlevania while hunting Devils, or a character like Terra or Aqua from the Kingdom Hearts universe encountering Castlevania on their travels across worlds. Not saying those specific characters should be included, but their presence could be explained by the mechanics of their respective universes, so they make good examples for what I'm trying to suggest.
5.) All the characters can talk. Except Simon. 'Nuff said.