It's a six-drop in a color combination that does not get any mana acceleration, but if you do drop it, it will definitely make a splash. I rounded up every good Imp, Devil, and Demon I could from recent sets.
The deck has many ways to ping the opponent, and also multiple ways to give all creatures solid abilities. If I get to drop both Theros enchantments, all of my creatures have Haste and Lifelink. I have too many big critters because of the creature constraint, but the deck still works well with them.
I have a reasonable number of creatures to trigger Cavalcade of Calamities.
This is a modeled, solitaire game. I would love to play this deck against a real opponent on MTGO, but I would never get to cast Rakdos against the most over-powered decks commander can offer.
Heartless Summoning is great in this deck... really great, actually. I miss-played Soulflayer since I cast it minus Delve, latter is the way to get a bunch of abilities on it. I played a lot of Soulflayer when it was in Standard. That was a lot of fun. Curse of the Pierced Heart is perfect for this deck, especially to enable Ravnica II Rakdos.
Sin Prodder is fantastic. In these modeled games, I always made it draw me cards. I am not sure which way a real opponent would have gone, although my bet will be on NOT letting me draw extra cards.
Here is a properly cast Soulflayer with Flying and Trample.
I don't get many chances to cast my big critters, and I mostly discard them for Soulflayer, but once in a while I get to tutor with Rune-Scarred Demon.
It's fun to fill the board in solitaire to see all the possible interactions. Erebos is fantastic, especially with some Lifelink on the board to replenish the loss from drawing all those extra cards.
Here is a Soulflayer with Flying and Trample from Delve and Lifelink from Whip of Erebos.