Tapeenon, the First Hellion

Devour 3, Wallkiller.
Whenever a creature entering a battlefield
activates an ability, activate that ability twice
instead.Whenever an opponent takes non-combat damage, they take twice that much damage
instead.
{2}{x}: Play target creature in your graveyard that creature gains a demon counter, that creature
cannot lose any demon counters. X is equal to
chosen creatures converted mana cost and how
many demon counters that creature has.