Ugin's Cave

Ugin's Cave cannot enter the battlefield by an ability or spell. You may only play Ugin's Cave when Legendary Lands named Kozilek's Tower, Emrakul's Domain, and Ulamog's Sanctum exist in your graveyard.
{t}: Add {c}{c} to your mana pool. Untap Ugin's Cave during your opponent's next untap step.
{5}{c}{c}{c}{c}: Exile three Legendary Land cards with different names from your graveyard: You win the game.