Galina, Wanderwine Keeper

Whenever Galina, Wanderwine Keeper deals
combat damage to a player, you may exile a
Merfolk you control. If you do, take an extra
turn after this one. Skip the combat step of that
turn.
Whenever Galina, Wanderwine Keeper leaves the
battlefield, returns all cards exiled with Galina to
the battlefield under their owner's control.