I've always loved Sonic Eagle. I'd like to see Updraft and Flare as well. Sonic Drive would also work depending on how they do it, or Sonic Wave. Either one could be his Side-B so he can keep Spin Dash as his Down-B. Or it could be the Advance games' somersault like P:M did recently.
But even his 3 hit combo and dash attack could benefit from using Battle's 3 hit attack and Sonic Windmill.
...If anyone hasn't noticed, I'm part of the rare species that absolutely loves Sonic Battle. XD
Speaking of which, anyone else here ever play that one japanese fan-game, Sonic Battle Lost Ending Neo? The one with a weird title but awesome fighting system?
Shame 3.0 with Chaos never got released, though. >>