Round 5 submission, ARENA MASTER (bonus, although on ally as well):

New ability square: "All squares of this type form arena. If there are enemy and ally in opposite corners of it, and your target has (inside arena) free adjacent square, you can make them fight. The non-target is teleported to that free square, and then they both use abilities / attacks vs each other, on their respective positions (if they have any)."

Comments / ideas for the piece:

• If more pieces have to die, maybe they shouldn't be always from same side.
• Wide coverage, but that doesn't mean it's easy to use, both "corners" need to have fighter.
• AM can make allied close fight specialists cut the distance if it's advantageous.
• Or, find non-threatening enemies, to be ported away from safety of their own / back ranks. Porting dangerous enemy that survives the fight gives him the next turn to make you pay.
• AM himself isn't great vs long range threats, so he "carries" the risk for allies, finding positions and battles for them.
• Order of free space for teleport would be - (1) closest to AM (2) if two have same distance to AM, one of those closer to center of the board.
• Target attacks first. Both fighters apply the attack / ability, even if one / first kills the other, similar how Wisp takes revenge despite dying from the attack that preceded Wisps's.