Each fighter in Lethal League seems to have a different special ability which can be activated once the special bar is filled by a few hits on the ball. For instance, Raptor's steam trading card describes the following:
Raptor is a rookie in the Lethal League scene, hailing from the south. Though young, he’s very determined and fiercely competitive. His weapon of choice is a metal baseball bat and his special ability allows him to twist around and quickly hit the ball two times in a row.
I've seen this in action in the game. I also know that it's triggered by double tapping attack on the ball. I've figured out that Switch's special is triggered by tapping jump again while in the air, but can't really work out what it does specifically. I've also seen Latch eat the ball during his special and become able to spit it out in any direction again, but I have no idea how to trigger this when playing as him.
What do each of the special abilities do, and how are they triggered?