Elden Beast

Whenever a non-token creature dies,{3} you may exile it . If you do, create a 2/2 black and white Great Rune artifact creature token with flying. You can only create up to three Great Rune tokens this way per turn.

Whenever you gain life, return a creature exiled with Elden Beast to the battlefield under your control.

At the beginning of your end step, if you control 7 or more Great Runes, you win the game.