Tormentor of Dreams

Flying, deathtouch
Ambition 4 {5}{b}{b} ({5}{b}{b}, Exile the top four
cards of your library: If Tormentor of Dreams isn't
ambitious, put four +1/+1 counters on it and it
becomes ambitious.)
As long as Tormentor of Dreams is ambitious,
you may play Nightmare and Demon creature
cards exiled with Tormentor of Dreams.