Death from the Forest

Target player puts a +1/+1 counter on a creature they control, and sacrifice it. Put X +1/+1 counters on Dednap, Void of the Grove where X is the number of +1/+1 counters that were on the sacrificed creature. If the sacrificed creature's power plus it's toughness weren't greater than Dednap's power, you may copy this spell and cast it without paying it's mana cost.
It is said that Dednap himself will unleash his powers on those who come to him seeking power, but do not conform.