May I ask, is Vanguard Princess off the table too? And also: http://www.spriters-resource.com/pc_computer/fuukataisen/ Fuka Taisen sprites.
Also, I have a few suggestions. You may not like all of them, but it's rare I have the chance to make them.
Crimson Alive: Extreme Encounter.
mugenguild.com/forum/topics/crimson-alive-extreme-encounter-character-sprites-and-sounds-116848.0.html
I like some here express an interest in this game getting more love in Mugen and with I believe Toshio having worked on a Towa, Rubette having already been made and Ren I know in our forum already, I support you having a crack at more of the characters from this.
Suggestions: Lieyan, Nightphobia, Jane doe.
Vanguard Princess.
I believe you already have sprite files from it, as I hope so seeing as I cannot find more sprite files around.
You've already worked with this, and while a little more detailed, these sprites are still a step down from some I bet such as BB/P4A. I'd like to see the roster finished off and with Natalia finished by another creator, not many left to go.
Suggestions: Kurumi, Haruka, Hilda.
Super Strip Fighter IV Characters -without- NSFW frames.
It'd be fun to have a playable, interesting character from one of these, without the NSFW frames that causes most of the characters to be sneered at a little. Plus, you might be able to make them a little more... uh, individual I guess. Imagining any of these with the systems you've used for other characters intrigue me. Character Suggestions: Mari, Ran or Sayaka. And if you feel like it, Yuri already exists, but as I said, your spin on it would be cool. http://mugenguild.com/forum/topics/super-strip-fighter-4-sprites-115434.0.html