The Cauldron of Eternity
Oracle Text
This spell costs 2 less to cast for each creature card in your graveyard.
Whenever a creature you control dies, put it on the bottom of its owner's library.
2B, T, Pay 2 life: Return target creature card from your graveyard to the battlefield. Activate this ability only any time you could cast a sorcery.
Besides that I don't see it having much use, you really don't want this in multiples typically and you don't need it early. A 1 or 2-of in sideboards for grindy matchups, pretty strong at that if graveyards are easily filled up.