Death

Double strike, Flash
{1}{g}: Regenerate Death.
{3}{b}{b}, Exile Death: Choose a creature type.
Return all creatures of the chosen type from your graveyard to the battlefield.

Whenever a creature dealt damage this turn by
Death dies, put a reap counter on Death. At the beginning of your upkeep, if Death has 3 or more
reap counters on him, transform Death.