Sek'Kuar, Deathkeeper I think that the secret to breaking this card lies in being able to consistently sacrifice one or more creatures every turn. The best way to do this, I think, is with Recurring Nightmare and several creatures either with haste or useful comes-into-play or leaves-play effects. Something like Spark Elemental appears tempting and it might be worthwhile to include it, but I think that most of the creatures in the deck need to actually stay in play so that they can be cycled in and out of play with Recurring Nightmare. Anger and Brawn, on the other hand, seem like good options to me. Being able to swap a pair of Imperiosaurs in and out of play as 5/5 hasty tramplers, getting 3/1 tokens from Sek'Kuar each time is probably a good goal for this deck. The colour selection is good for a deck of this sort. Black gives access to Demonic Tutor, Diabolic Intent, and Buried Alive. Green gives access to Worldly Tutor. Red will probably be the minor colour here.