Soul Stone

{1}{b/g}{b/g}: add a soul counter on Soul Stone.
{t}, remove X soul counters: exile up to X cards from
any graveyard. Sacrifice the creature with the
highest converted mana cost you control and put
any exiled creature with converted mana cost X or less onto the battlefield under your control. It fights target creature you don't control.
Sacrifice six infinity stones with different names:
you win the game.