Looks like a solid start, couple notes:

1. Rakdos Charm on the SB for sure, it does damage to YOU too.
2. Not sure about MB Whip of Erebos and Mizzium Mortars , up to you though, they're not bad, just given this is aggro they shouldnt be neccessary. The whip would be great for a mirror match, unless youre just using it for its whip-in effect.
3. Put Read the Bones on the MB so that you have some sustain.
4. Get some Fanatic of Mogis , youve got so much devotion that you can play him as a total bomb after a few turns.

Anyhow, thats my take on the deck

Whip of Erebos is to both whip in creatures that find their way in to the graveyard, and also for a little life-gain along the way. Best case scenario, I'll be attacking with a lot of creatures as often as possible, so even if they get blocked I'll at least gain some life even if my opponent doesn't lose any.

Mizzium Mortars is just one removal option. I have plenty in Rakdos colors. It can take out a Blood Baron of Vizkopa for just 2 mana.

I don't have any Fanatic of Mogis currently, and I'm not sure if I can maintain a lot of devotion turn-to-turn to have that be reliable. I expect any creatures I get out (which would be my only devotion source) would die not long after I bring them out, so that's iffy.

I could use sideboard help. I want to put Slaughter Games in, but what to take out?

Also: mainboard Diabolic Tutor ?

What about Pack Rat ? I like the idea of discarding Slitherhead or an extra land to get even more creatures out, but do they fit the theme?

In testing, it does what aggro decks predictably do: a disgusting amount of damage very quickly and then my hand is empty and not much else happens after turn four besides playing land. I think adding Read the Bones may be necessary, but again, what to take out to make room for it?

I tested this deck in between rounds at last weekend's pre-release against other players' Standard decks, and it went undefeated, but I have the suspicion that they weren't using their competitive decks, just their Standard-legal casual decks.

Turn one: Rakdos Cackler unleashed; turn two: Spike Jester , swing for 5; turn three: Madcap Skills and bloodrush with Rubblebelt Maaka during the attack for 11 damage total; turn four: really anything else, but Rakdos, Lord of Riots elicits a scoop pretty reliably.

Made some changes to improve consistency and speed. Will update the list soon.

I'm planning on taking it to a Standard tournament this Friday, so any suggestions on how to beat the current meta are welcome.

Mogis and Purphoros... no wait, Purphoros and Rakdos! I like that interaction in particular. Put down a little cackler, put down his master, all on turn five. 4 damage right off the top. Not to shabby at all. Personally like Underworld Cerberus as well, but I wonder if it's too slow for the deck, but the interaction it also has with Purphoros is just too nasty.

One thing that comes to mind is taking a 4th copy of Madcap Skills or even siding in that Ash Zealot vs. your one Fanatic of Mogis . It would add more constancy vs. fanatic's so so damage when he comes out. However, my main concern is you have so many hot cards at four drop slot already that they all make fanatic the weaker option. Exava, Rakdos Blood Witch vs. fanatic? or maybe Mogis, Purphoros, even Rakdos? I think your 4 drops are very good as is, and making this deck even faster with the reach those cards will only help out more.

I've thought about a fourth Madcap Skills . This deck's early turn destruction with Rakdos Cackler and Spike Jester mad-capping for 10-12 damage per turn is delightful.

Underworld Cerberus and Rakdos, Lord of Riots have always been dead cards, I'm thinking of dumping them for Magma Jet or something.

The Fanatic of Mogis was a recent addition to try out. Sometimes it's good, sometimes just so-so.

I have a couple Archetype of Aggression now too, and I've been trying them out. When a mad-capped Spike Jester does get blocked by a couple 1/1 tokens, the trample makes me feel a lot better; plus, the archetype ups the devotion just a bit more.

In a game I played last night with it (vs. a control deck). I had the Archetype, Purphoros, Mogis, a Cackler, and a Spike Jester attack. Cackler, Jester, and Mogis(!) all had Madcap Skills enchanting. I paid 6 mana into Purphoros's pump ability. The damage total was 38 all trampling.

Opponent used Riot Control . . . but, he had no blockers besides a bunch of 1/1 soldier tokens, and no effective removal, so I just kept doing the same until it finally got through.

It is too bad that Cerberus and Rakdos haven't been working out. Magma Jet isn't a bad choice, but I'd also consider bringing in more beaters like Ash Zealot or maybe even Guttersnipe with all the spells you're throwing around.

I like Guttersnipe a lot. I have like 7 of those things; I don't know why it's not in the 'maybeboard' . . .

It's likely that it just doesn't feel like a Rakdos creature, ya' know? Also, a prior incarnation of this deck was more creature-heavy. This update has more instants, but I wouldn't know what to trade out for it.

'snipe features prominently in this deck's alter-ego: Disco Inferno though.

I think I only have the one Ash Zealot , and while it is a solid card. I don't know how to make room for it.

Hey, thanks for the comment on my deck, Rakdos Aggro (FNM Success 3-0)! I also placed 4th after 3 matches, even though I went 3-0, and that was due to a single round loss in my first match to a kid at my local FNM who's pretty good... he just happened to do really bad that night, bringing my score down.Some things I'd recommend:Ultimate Price in the MB, possibly? Depending on your metagame, it might be a wise move. A lot of the people at my local store tend to play creature heavy decks, so it's come in handy often.Thrill-Kill Assassin makes a great blocker against R/G Monsters.Peak Eruption : not sure how I feel about this card... I did have it in my sideboard for a few days, but my friend convinced me to take it out. Probably one of my better moves, too. Land set-back is great and all, but I'd consider popping a Doom Blade , Skullcrack , maybe even Erebos, God of the Dead ; Skullcrack works great against U/W/x control decks.

I've been considering Skullcrack for the SB.

After a lot of play-testing vs. my mono-black deck (which, admittedly, needs more Desecration Demon .. [see: Devoted to the Dark Realms ]), this Rakdos deck pwns pretty hard. I did 3 best-of-three matches and Rakdos only lost 2 games out of 8.

The damage is fast and unrelenting.

I can cannibalize the black deck's sideboard for Erebos and more kill spells, but I've found the 4 Dreadbore s, 2 Mizzium Mortars , and 4 Lightning Strike are enough to clear the path.

I really don't know how to make it better, but I know it still has weaknesses.

After playtesting this extensively last night and receiving some constructive criticism, I am considering the following:

 -2 Hellhole Flailer
 -1 Exava, Rakdos Blood Witch
 -1 Mogis, God of Slaughter
 -1 Rakdos's Return
 -2 land

..

 +1 Madcap Skills
 +2 Magma Jet
 +4 some combination of the following: Gore-House Chainwalker
Ash Zealot
Tormented Hero

Is this a good idea to speed up the deck and focus on the early-game aggro?