Zenitsu Agatsuma

Haste, First Strike
At the beginning of your upkeep put a breath counter on Zenitsu
Thunder Breathing First Form - Thunderclap & Flash: remove a breath counter from Zenitsu, if a breath counter was removed this way he gets +3/+0 and "when this creature attacks it deals 3 damage to target creature defending player controls." until end
of turn.
When this creature dies exile it and return it to the battlefield transformed.