Arena of Undeath

{1}{p/b}{p/g} return target creature from your graveyard to the battlefield except it is a 1/1 black zombie (it retains its other abilities) and put a necromancy counter on Arena of Undeath then if Arena of Undeath has 13 or more necromancy counters on it remove all counters from it and put all creatures in graveyards to the battlefield under your control