Eye of Doom
{4}
Artifact
Oracle Text
When this artifact enters, each player chooses a nonland permanent and puts a doom counter on it.
{2}, {T}, Sacrifice this artifact: Destroy each permanent with a doom counter on it.
Watch Out
ETB trigger, not a cast triggerRules Note
This card's ability triggers when it enters the battlefield, not when it's cast. Effects that double ETB triggers (like Panharmonicon) work here. Countering the spell prevents the creature from entering, so the ETB won't fire.