Encroaching Darkness

roll a 20 sided die then add that many counters to this card, remove one counter each turn when the counters become 0 deal X dmg to target player X being the number rolled on the 20 sided die.
when the counters reach 0 exile all creatures with a defense of 2 or less
come little children, come away with me, come to a fantasy filled with misery, I wont hurt you not one bit, I'll let mother darkness see your fit