The Soul Stone

Legendary Artifact — Infinity Stone

{1}{B}

Indestructible {T}: Add {B}. {6}{B}, {T}, Exile a creature you control: Harness The Soul Stone. (Once harnessed, its ∞ ability is active.) ∞ — At the beginning of your upkeep, return target creature card from your graveyard to the battlefield.

Rulings and every printing on Scryfall