Anguished Hell-Gate

At the beginning of your end step, sacrifice a creature.
Whenever a creature you control dies, put an agony counter on Anguished Hell-Gate.
{b}, Pay 2 life, Discard a card: Return target creature card with power less than or equal to the number of agony counters on Anguished Hell-Gate from your graveyard to the battlefield. It gains haste.