You've also got plenty of creatures that give you a bonus when they die: Goblin Arsonist and Gang of Devils deal damage, Maalfeld Twins replaces itself with a couple of Zombies, Driver of the Dead raises a creature from the dead.... As if that weren't enough, cards like Harvester of Souls, Blood Artist, and Havengul Vampire provide bonuses when any creature dies, no matter whose it was.
Ultimately, you'll have such complete mastery over death that sacrificing your own creatures will be a benefit in disguise. Barter in Blood, Bone Splinters, and Fling are all cards that allow you to kill your opponent's creatures at the cost of killing your own. This may seem fair, but while your opponent's creature stays dead, your Butcher Ghoul comes back from the grave and Harvester of Souls nets you multiple cards. Now that's truly evil.
To make this deck even more diabolical, consider bolstering it with Killing Wave, a black sorcery with the potential to kill all creatures or shred your opponent's life total. Hound of Griselbrand is another nasty choice, as it has both undying and double strike. Finally, Vexing Devil gives your opponent the choice of facing down a 4-power creature or taking 4 damage-all for just one mana!