Took this to FNM last night (first time back in about a month, and the first time I played this deck) and went 3-2 overall. Of the two losses, one SHOULDN'T have been but I just made a really dumb play that costed me the match. The other was to a UG Soulbond Hexproof/Unblockable list that simply just had no way to interact with. The good thing is that it simply doesn't lose to aggro, which was the plan. Rakdos aggro, kibler aggro, gw aggro, bg zombies all tried last night and failed. Even grinded bant control out for a win (I played quite a few games before we started and played a few in between rounds).
Against aggro, you simply 1-for-1 all their early stuff. From there they usually begin to panic and play around stuff. They usually either begin to flood the board in hopes of you running out of spot removal, in which case you hit them with Magmaquake, or they hold back in the hopes that they can draw their big game, in which case you hit them with a massive Rakdos's Return. From here you start to beat down with a Rakdos Keyrune or a Lone Revenant and dig for a Homicidal Seclusion.
Against midrange decks, you can usually play a similar game since their removal can't hit Lone Revenant unless it's a Bonfire of the Damned which (usually) can't hit a Rakdos Keyrune anyway. The main difference is that your smaller spot removal isn't as good unless you're using them with the distroy spells. Rakdos's Return for their hand size is a complete blowout, however. The cards I'm most worried about in midrange decks are sigarda, host of heron which I can't deal with without sb cards, and Loxodon Smiter, which I have to deal with twice if they're holding it when I Rakdos's Return them. Thragtusk can be annoying, but it's not a big deal overall because of the Rakdos Keyrune, and unless they're playing Rhox Faithmender and I don't have something to deal with it right away, but otherwise I can gain more life each turn.
Still tossing up between fitting in either a Curse of Echoes, Witchbane Orb, or Grafdigger's Cage in the sideboard, depending on my other midrange/control matchups.
