What better first post to make here than the newest incarnation of the new Red-Black Guildleader.
Rakdos, the Showstopper 4BR
Legendary Creature - Demon (M)
When Rakdos, the Showstopper enters the battlefield, flip a coin for each creature that isn’t a Demon, Devil, or Imp. Destroy each creature whose coin comes up tails.
Not my favorite card so far, nor do I think it really shows what the Cult of Rakdos is all about, but might be fun to play with.