Ob-Nixilis Bloodson

Fly, menace, protection from white and green.
Whenever a creature die or you lose exactly 3
lives, put a +1/+1 counter on Ob-Nixilis.
Whenever Ob-Nixilis attack, it gains Anihilator
X, where X is one third of the counters on Ob-Nixilis rounded down.
Sacrifice a creature, pay 1 live: Draw a card, you
may pay 2 lives. If you do, create a treasure
token for each other demon you control.