Magic : The Gathering (MTG) : Armageddon Clock - (Antiquities) - U (SPLD-PLD)

Artifact

At the beginning of your upkeep, put a doom counter on Armageddon Clock.

At the beginning of your draw step, Armageddon Clock deals damage equal to the number of doom counters on it to each player.

{4}: Remove a doom counter from Armageddon Clock. Any player may activate this ability but only during any upkeep step.

Illustrated by Amy Weber.