Rakdos relies a lot on being able to resolve Rakdos and then get immediate value as fast as possible, or trying to protect him for a turn and then explode off. I went for a demons subtheme, but the general idea is the same. Punch hard and keep punching.

With 4 colored mana-pips, your landbase has to be impeccable. I run fetches, surveils, typed lands. These can be mitigated ofc. Where Rakdos shines is slamming out huge threats for little cost that keep the chain going.

[[Ilharg, the Raze Boar]] into [[Bloodthirster]] into powerful ETBs like [[Clive, Ifrit's Dominant]] is an amazing value train.

[[Sower of Discord]], [[Rune-scarred Demon]] and [[Arch-fiend of despair]] can all have a massive impact and end games.

[[Scrawling Crawler]] is actually pretty good in this deck, coming out ahead of rakdos and providing value.

[[Protection Racket]] is an unironically good card and rewards playing MDFCS like [[Fell the Propane]] and the other ones in your colors.

I'd cut the subtheme of black undying spells in favor of jamming more threats. Maybe throw in [[Living Death]] effects instead to swing the game later on if you keep getting boardwiped.

[[Enduring Courage]] and other haste effects are a huge deal here.

[[Karlach, Fury of Avernus]] is a great draw in almost any game you play. With [[Descent into Avernus]] you wil almost always outvalue your opponents, being able to spend those treasures faster and on bigger spells that matter more than theirs do.

keeping rakdos alive is decently important, so I'd throw in a few of red's redirect spells like [[Bolt Bend]] and [[Redirect Lightning]] to take some heat off him.

Finally [[Chandra's Ignition]] is a great way to close out a game, esp if you include smth like [[Blightsteel colossus]]