Colt, The HitKiller

Colt, The HitKiller comes into play with five annihilation counters. Equipped creature gets
+5/+0 and has "Whenever equipped creature deals
damage to another creature or player, remove an annihilation conter from this artifact and the
creature dealt damage loses all abilities and is
destroyed, if a player took the damage, then that
player lose the game."

Equip {8}