Kitchen Finks - This card is insane. It is a three drop that stabilizes against aggro decks, and can be sacrificed twice with
Elder Deep-Fiend.
Reflector Mage - The exact tempo card we needed. Can take out a creature for a couple of turns, and you don't mind sacrificing it. Also, the way this deck is constructed, there is a good chance that they won't be able to cast it again:
Play Reflector Mage, bounce Tarmogoyf, for instance. Pass the turn. This turn, they won't be able to cast the Tarmogoyf. You untap, now with 4+ mana, and pass the turn. Stop on their upkeep, cast Elder Deep-Fiend tapping them out. Continue chaining Elder Deep-Fiends together, and they won't be able to cast that creature ever again!
Tireless Tracker - I noticed, that sometimes this deck can get a bit flooded with 22 lands and 8 mana creatures. To compensate, I added Tireless Tracker for some additional card draw and a mana sink.
Eternal Witness - When chaining elder deep-fiends together, I noticed that a lot of the time, you just sacrifice the old one to the new one. This is just a way to get more Elder Deep-Fiend triggers. Also, if you don't have 3 elder deep-fiends in your deck, this can be the last search target for Congregation at Dawn to get back a diseased Elder Deep-Fiend.
Sylvok Replica - One of the worst card in the deck, but it provides a main-deck out to Blood Moon and Ensnaring Bridge. Can be fetched with Sanctum of Ugin, and still counts as a 3 drop.