Graviton, The Endless Hunger

Indestructible, protection from colored spells.
As long as Graviton The Endless Hunger is on
the battlefield, lands your opponents control do not untap during the untap step.
{3}, {t}: Exile target land an opponent controls, then put a 1/1 colorless Singularity creature token onto the battlefield with "Sacrifice this creature, destroy target colored creature".