Argon, King of Demons

X: Put a +1/+1 counter on all creatures you control that are demons, gain 1 loyalty for each counter placed this way.
-4: Destroy target creature, then return it from the graveyard under your control, it is now a demon as well as it's other types.
-20: Gain an emblem that says, "Whenever an opponent takes damage from a demon, they lose the game."