It looks pretty good. Here's a fun combo you might like;
Korozda Gorgon with any undying creature. The benefit is that it lets you sac the same creatures multiple times and they will ALWAYS come back. For example;
Korozda gorgon and
vampiric rites with
geralf's messenger means that you can sac your messenger (1 mana), it'll come back automatically, use your gorgon's effect (2 more mana), then sac your Zombie again with your enchantment and have it return to the field (1 more mana). So basically you could spend 4 mana to draw two cards, gain 2 life, -2/-2 a single creature and make the opponent lose 4 life in just one turn. Look into the other black or green creatures that have Undying and you'll find some other cool combos.