This artifact enters with three arrowhead counters on it. At the beginning of your upkeep, if there are no arrowhead counters on this artifact, sacrifice it. {T}, Remove an arrowhead counter from this artifact: Put a -1/-1 counter on target creature.
As this artifact enters, choose an opponent. At the beginning of the chosen player's upkeep, this artifact deals X damage to that player, where X is the number of cards in their hand minus 4.