Nexus, Envoy of Oblivion

Indestructible, protection from colored spells.
Nexus Envoy of Oblivion enters the battlefield with 5 Oblivion counters.
At the beginning of each end step, remove an Oblivion counter from Nexus. When there are
no Oblivion counters left on Nexus, sacrifice Nexus. All players exile all colored permanents they control and all cards in their hands.