If your not against what seems like the opponent with the ability to perform continuous stun. You get either the opponent that heals to full health every time any of their teams touched or you get the opponent that seems to be able to buff even when you use a character with a skill that blocks buffs for a certain amount of turns.  Not sure if we have and Arena reset but if it's a reset on everyone seems odd we still remain in the groups we were in before the reset master class enemies at challenger would've seemed more sufficient making it to where everyone started at 0 without separating like when we all start the arena