The Kadoris Trio

At the beginning of your upkeep, each player may choose a creature or artifact card in that their graveyard and put those cards onto the battlefield under your control. At the end of the turn, each player shuffles their graveyard into their library and gain 1 life for each permanent they control, but do not own.
A player may pay {4} at any time. If they do, they gain back control of permanent you controlled.