Eyes in the Abyss

Eyes in the Abyss enters the battlefield with ten Awakening counters on it.
When a creature an opponent controls attacks, remove one Awakening counter from Eyes in the Abyss.
{6}{t}, sacrifice Eyes in the Abyss: Create a Frozen Watcher, a legendary 10/10 colorless creature token with indestructible and menace. Activate this ability only if there are no Awakening counters on Eyes in the Abyss.