R/B Control deck attempt

Sadly, Lord Rakdos doesn't really get it done in constructed play outside of EDH (then again, he was designed with EDH in mind...).  I'd suggest dropping him and the Shimian Specters for more Desecration Demons.  They're a total pain to deal with and, in many respects, work beautifully as removal engines.  If you're wanting to run Lord of the Void or Necropolis Regent, I would suggest putting in a few Crypt Ghasts in otherwise, as Hikingstick says, you'll likely never get them on the field.

Just as a thought, with Faithless Looting in here, why not some reanimation or 'yard based stuff?  I'm thinking either Rise from the Grave or you could splash a pair of Godless Shrines and throw Unburial Rites.  In either case, getting those high cost creatures into the yard with faithless looting is good fun, to then turn around and drop them onto the field anyway (often at a lower cost).

Lastly, I'd look over your SB and really be sure that the cards all address specific match-ups you'll be running into.   For instance, Slaughter Games I can see, but the others?  If you need land hate, why not toss in a few Ghost Quarters in the SB?  Personally, I'm a big fan of Brimstone Volley for its ability to hit the opponent for 5 if they take out one of your creatures (or in this case, thanks to Desecration Demon, you might be hitting morbid triggers pretty frequently).  Along those same lines, Skirsdag High Priest could prove to be a beast.

Anything is worth a shot.  Spend some time playtesting and see how it does.  Good luck!

The double symbols when paired with the damage requirement to cast him, you'll get stuck with him in your hand unable to be played far more frequently than a Desecration Demon.  That's an awful lot of work for a creature that isn't that hard to take out.  And, considering he would only help you with two creatures in the deck, his added abilities really don't make that much of a difference either.  Meanwhile, Desecration can serve as a multiple removal spell/morbid trigger.