Not yet decided ;)
Do you have any suggestion?
I think a character that has slow mobility and lacking combo potential but massive damage would fill in an empty slot relatively well. We have:
Kiki - Ranged controller
Pepper - Weak setup character with complex combos and dragging moves
Sinbad - Combo speedster
VGSage - Good damage with powerful combos
I think something similar to a shadow warrior would fit the role pretty well. Here's an image for my concept - his name is Igbik.
He uses his Jade Sword to deal massive damage and start strong combos relying on momentum. It's hard to find an opening with how slow he is, but if he can find one, you're in for a tough time. (I'll make more sprites if you like the concept)