Demon Titan of Xathrid

Whenever you cast a demon spell, put two +1/+1 counters on Demon Titan of Xathrid.
Emerge {5}{b}{b}
Demon spells can be cast as if they had emerge. The emerge cost is equal to its converted mana cost. (You may cast those spells by sacrificing a creature and paying the emerge cost reduced by that creature's converted mana cost.)