Jhen Mohran

Trample, Menace, Ward - Sacrifice a Legendary Artifact.
Jhen Mohran enters the battlefield with 3 imminence counters on it. At the beginning of your upkeep,
remove an imminence counter. When the last
counter has been removed, destroy all other creatures
and artifacts, and deal 7 damage to each opponent.
{5}: Place an imminence counter on Jhen Mohran.
Any player may activate this ability.