Demon Supremus

Menace, Mutate 2
At the beginning of your upkeep, sacrifice another creature. Put X +1/+1 counters on
Demon Supremus and each opponent loses X life, where X is the sacrificed creature's toughness. If you can't sacrifice a creature, tap Demon Supremus. It must mutate this turn, and when it does, it deals damage to you equal to its power.