Buff the really shitty stuff like high tech, master of storms, dualist, unbreakable, Kitana's face, Bo Rai Cho.
Buff Tanya:
Universal: F3 is 16 frames
Drill kick and flip kick back to its original state
Pyro:
Ex fireball (ground) now does 12% damage
F3 now does 13% damage on shrouded opponents and fireballs can still be used afterwards.
Gap in b312 is removed.
Ex shroud now stuns to continue combos (like Ex Tonfa).
And finally more strings (one of which being a true mid attack)
Kobu:
B12+4 now does it original damage
Ex Tonfa does increased damage (and scales significantly less) Tanya now throws both Tonfas (comes with a slightly altered brutality animation)
B12+42+3 now does increased damage.
Dragon Naginata:
Ex bf2 now has armor
Pogo has more hitstun
Pogo more + on block
One or two more strings
Pogo 1 now bounces vertically allowing for midscreen combos.
Honestly, this would never happen but I would just take her teleport out of the game and add one unique special to each variant. So Pyro would have find me which makes Tanya go invisible and all her attacks do more damage and she has slightly faster movement and attacks+ fireballs come out faster. DN would get an air flip move that allows her to get across the screen flawlessly. Kobu could almost rock without something new. I'd just give it a low Tonfa toss. All really cool moves each useful.