I think that Satyr might be good. One of the problems with red is that pointing burn spells at creatures costs you a lot of aggression and you can stall out if they just keep throwing better creatures at you. I'm going to try him out. Also I think that Hydra is worth trying out too if the sacrifice theme is supported by your cube. Lastly, that Centaur-Oracle card looks pretty solid, but will destroy aggro decks.