The Rock/Paper/Scissors is just how the battles will be decided X3 It's the action fighting poses for the attacks you use when you win.
That would be pretty funny though, just suddenly a tidal wave of Tapastic characters turn up bursting through the door.
In terms of characters I'm not 100% sure at the moment, there's not many characters who are actually fighters, at least not yet X3 however I've got a couple of ideas for starry day inspired characters