As someone who loves this commander, I've got a few enablers to throw at you. I would advise against guttersnipe unless go instant/sorcery heavy- I like using Rakdos, Lord of Riots to cheat out fatties (mainly eldrazi).
Thermo-Alchemist- he pings everyone. He's got a decent butt, so you can always keep him back to block and ping at the EoT before yours. Aided by instants but not reliant on them.
Nettle Drone- Pinger with an untap like thermo. It's pretty abusable with colorless beaters.
Lobber Crew- Pinger that untaps when you cast your general. Essentially lets you cast a Wurmcoil Engine for free when Rakdos hits the table.
Goblin Sharpshooter- Ping with conditional untap. He destroys tokens and works well.
Plague Spitter- Ping at upkeep, creature removal, and pings again upon death. He's one of my favorites.
Acidic Soil- Destroy's ramp decks and can win games. It's more of a meta call, but has pulled my butt out of the fire enough times that I kept it in. I'd run price of progress, but I run a fair amount of non-basics.
Chandra, Pyromaster- Ping + removal + can't block ability wins me over. She's card draw if you need it. I will never use her ultimate. My favorite Chandra for this general- I don't like the flip walker version because it seems too conditional and doesn't impact the board enough.
Stuffy Doll- It's a pet card, but usually gets cast for free. A great blocker that makes people leave you alone. Also works really well with blasphemous act
Ob Nixilis of the black oath- Ping + life gain, evasive creature creator, and an ultimate that will win you the game.
Palace Siege- either Ping + life early in the game, or get back your threats later in the game.
Endbringer- ping + removal every turn, locks out attackers + blockers, and draws cards. As long as the manabase and support it, it's good.
Sorin Markov- Can win the game by himself if you can set someone to 10 and ping them to death later. I've never used the ult.
Indulgent Tormentor- He's either ping or card draw. At the end of the day, he hits for 5 and flies. Sin Prodder could probably replace him, but I think it can screw you over more than it can help you.
Decimate works great in my Xenagos, God of Revels deck. Most of the time you wait for an enchantment to hit the battlefield so you can play Decimate, but in Xenagos, I can always target my indestructible god if need be.
To those saying Berserk is too powerful to be reprinted, and it would mess up drafts- you do realize Temur Battle Rage was common, right? I dare to dream. It would be a cool rare/mythic.
Heliod- White control/good stuff.
Purphoros- tokens.
Nylea- Green stompy.
Thasa- Sea Monsters.
Erebos- Black good stuff.
Ephara- Blink (but it almost always could be switched out with Brago for a better general)
Karametra- Ramp aggro with fatties on the top end, like Worldspine Wurm and Eldrazi.
Xenagos- Super aggro gogogo. Sometimes with an infect theme.
Mogis- group slug/griefer cards like Painful Quandary and the like
Phenax- Mill God with wall tribal. Eater of the Dead is almost always a GG.
Athreos- Cleric tribal.
Iroas- Weenie aggro.
Keranos- U/R control. Storm works better with spell slinger commanders like Melek and Mizzix.
Kruphix- U/G ramp with stuff like genesis wave and other big X spells. It really lost a bit of power without prophet, but still has plenty of ways to untap lands on other player's turns.
Pharika- I've never played against her, but the coolest concept that I've seen was an enchantress build on youtube. https://www.youtube.com/watch?v=Hm4o7-Y7zew
I've always been partial to cards like Silent Arbiter and Crawlspace. Paired with Maze of Ith, Kor Haven, etc you can really screw with people's combat math. Recurring fogs in an Angus deck seems on flavor though. Extra turns are some of the best ways to build loyalty on planeswalkers, but tend to make people target you all the harder. Board wipes make most planeswalkers happy as well.
Also, tax effects from Propaganda, Ghostly Prison, and Collective Restraint don't tax people when they attack your planeswalkers, as they are not attacking you.
If you've got a heavy enchantment build you can always try out Sphere of Safety as someone suggested above. Norn's Annex also taxes people to attack you and your Walkers, but in my experience, people usually just pay the life.
True enough, but you can also bounce two creatures with the Desolation Twin's token ETB (including artifact creatures). The Artifact Creatures don't trigger curio, but can be bounced by non-artifact creatures. My favorites are Solemn Simulacrum and Duplicant.
Helm of Possession works pretty well with Shirei, Shizo's Caretaker. Also, my favorite spot removal in black is tragic slip, which is pretty darn good. Maybe run a reanimation package for when you kill their guys to bring them back under your control?
I hate exiling my own cards, So my vote would probably find a place for Endbringer before Dread Defiler, but I see how he can be quite the bomb if you have enough ammo for him.
With the change, you can generate colored mana outside of your commander's identity now. So, they can cast your red cards provided they have an artifact that allows them to tap for the mana. The sky isn't falling, but Sen Triplets can drop stuff like Celestial Dawn now.
Gren08- Just be aware that if you add in Repercussion with Breaker of Armies, you might die unless you can give it first/double strike. I do run an abnormally large amount of creatures, but they work well with Rakdos and a good amount of my deck's draw engines come from me grabbing dudes back from my graveyard into my hand.
Also, Sire of Insanity put in an insane amount of work for me recently. He dealt with a player that kept buying back Constant Mists. It either baits out a removal spell that saves one of my fatties, or eats everyone's hand. With a Phyrexian Arena effect out, or an active Eye of Ugin, you take over a game pretty fast. I dropped Maga, Traitor to Mortals from my list for him- Maga can win games, but can only do so when Rakdos is out and doing his thing. Too often, Maga was sitting in my hand with that goofy look on his face making me whish he was anything else.
However, my group runs plenty of spot removal ever since I introduced them to Xenagos, God of Revels, so YMMV. If your group is prepared, they won't allow Maga Kills often. Warstorm Surge could work plenty well for a replacement, but I've won tons of games with that card and wanted to shake things up a bit.
So far, Sire of Insanity, Ugin, the Spirit Dragon and Void Winnower have been Prophet of Kruphix level power drops for me; You land them and the game turns into remove this permanent or die. I'm thinking of Playing Rakdos's Return, but I feel like the "target player" limitation might not be good enough for a multiplayer focused deck. Time will tell!
Repercussion is sick. Not only does no one block, but Red wraths turn into win conditions. Comic_Book_Joker, I could see Breaker of Armies doing so work to clear out tokens though. Temur Battle Rage was never drawn.
Burnt Offering was fantastic and I will never go back to Talisman of Indulgence. My favorite play with it so far is Sac a titan for tons of mana to save my graveyard---> Graveyard shuffled into library---> activate Eye of Ugin with the mana to get the titan---> play the titan after combat for free.
I had replaced Flame Rift with Acidic Soil a while back to combat the many ramp decks in my metta. Even if you don't play many ramp decks, I'd tell you to go for the switch. For one additional mana you do a hell of a lot more damage late game, and let's be honest, you're not going to cast Flame Rift prior to t4 anyway without Rakdos out there.
Sword of Light and Shadow was never drawn, but I can't imagine a case where I would have had it in my hand and not want to play it.
I may drop Animate Dead for Reanimate. The creature I Usually grab with Animate Dead is Rakdos, Lord of Riots, and he usually eats a naturalize at instant speed. Maybe I'll try and find room for both, but as it stands paying 4 life and a B for Rakdos looks pretty sweet.
I also managed to Cloudstone CurioOblivion Sower until I exiled everyone's library. It was a cheesy, yet cool victory, but I wouldn't make too big of a habit of it. The only other enabler I see that you're missing from your deck is Plague Spitter. This little guy lets you hold back all your other enablers in your hand while he mows down x/1 creatures every upkeep. He also combos with Repercussion and Whip of Erebos.
Bazaar Trader to give people guys, or permanently steal creatures with threaten effects
Grenzo, Havoc Raiser for the goad.
Stuffy Doll
Insurrection was a win con.
Homeward path to get back your commander and other things you may have given away.
edit: you can also try this for common commanders and suggestions on how to build them- http://edhrec.com/commanders/
Thermo-Alchemist- he pings everyone. He's got a decent butt, so you can always keep him back to block and ping at the EoT before yours. Aided by instants but not reliant on them.
Nettle Drone- Pinger with an untap like thermo. It's pretty abusable with colorless beaters.
Lobber Crew- Pinger that untaps when you cast your general. Essentially lets you cast a Wurmcoil Engine for free when Rakdos hits the table.
Goblin Sharpshooter- Ping with conditional untap. He destroys tokens and works well.
Plague Spitter- Ping at upkeep, creature removal, and pings again upon death. He's one of my favorites.
Retreat to Hagra- Ping + lifelink or can be used to give deathtouch to a goblin sharpshooter/Plague Spitter/any creature with trample. Negates damage from fetchlands and is pretty cool.
Acidic Soil- Destroy's ramp decks and can win games. It's more of a meta call, but has pulled my butt out of the fire enough times that I kept it in. I'd run price of progress, but I run a fair amount of non-basics.
Chandra, Pyromaster- Ping + removal + can't block ability wins me over. She's card draw if you need it. I will never use her ultimate. My favorite Chandra for this general- I don't like the flip walker version because it seems too conditional and doesn't impact the board enough.
Stuffy Doll- It's a pet card, but usually gets cast for free. A great blocker that makes people leave you alone. Also works really well with blasphemous act
Ob Nixilis of the black oath- Ping + life gain, evasive creature creator, and an ultimate that will win you the game.
Palace Siege- either Ping + life early in the game, or get back your threats later in the game.
Endbringer- ping + removal every turn, locks out attackers + blockers, and draws cards. As long as the manabase and support it, it's good.
Sorin Markov- Can win the game by himself if you can set someone to 10 and ping them to death later. I've never used the ult.
Indulgent Tormentor- He's either ping or card draw. At the end of the day, he hits for 5 and flies. Sin Prodder could probably replace him, but I think it can screw you over more than it can help you.
Bloodgift demon- a phyrexian arena that can "ping" someone to enable Rakdos
Staff of Nin- Ping/creature removal and draws cards.
Cryptolith Fragment- universal ping that can be flipped by sorin.
Shizo, Death's Storehouse- grants evasion.
Dragon Shadow- Cut Temur-Battle rage for this. Why? This comes back, grants evasion, looks cool in foil, and replaces a card I have in too many decks.
Cards that could also work in the deck well:
Tree of Perdition- good card, but sorin can win games by himself; this can not.
Shepherd of Rot- sick card, but it gets eaten by my plague spitter. I cut him.
Heartless Hidetsugu- best with lifelink.
Repercussion- if you're a madman. Works great with red boardwipes, but I'm creature heavy.
Purphoros, god of the forge- I run Clodesonte Curio. He made things too easy.
Hero of Bladehold needs to be in any token build that can fit it.
It also has splinter twin/kiki-jiki, mirror breaker with deceiver exarch, pestermite, zealous conscripts
Oh, and dualcaster mage with heat shimmer/twinflame/rite of replication.
A side combo of this is Nucklavee/archaeomancer with omniscience and with heat shimmer/twinflame/rite of replication.
Other cool combos in the deck are willbreaker with curse of the swine/descent of the dragons, but it's far from an auto-win combo like the above. Oh, and Mizzix's mastery is a combo all by itself.
Heliod- White control/good stuff.
Purphoros- tokens.
Nylea- Green stompy.
Thasa- Sea Monsters.
Erebos- Black good stuff.
Ephara- Blink (but it almost always could be switched out with Brago for a better general)
Karametra- Ramp aggro with fatties on the top end, like Worldspine Wurm and Eldrazi.
Xenagos- Super aggro gogogo. Sometimes with an infect theme.
Mogis- group slug/griefer cards like Painful Quandary and the like
Phenax- Mill God with wall tribal. Eater of the Dead is almost always a GG.
Athreos- Cleric tribal.
Iroas- Weenie aggro.
Keranos- U/R control. Storm works better with spell slinger commanders like Melek and Mizzix.
Kruphix- U/G ramp with stuff like genesis wave and other big X spells. It really lost a bit of power without prophet, but still has plenty of ways to untap lands on other player's turns.
Pharika- I've never played against her, but the coolest concept that I've seen was an enchantress build on youtube. https://www.youtube.com/watch?v=Hm4o7-Y7zew
Also, tax effects from Propaganda, Ghostly Prison, and Collective Restraint don't tax people when they attack your planeswalkers, as they are not attacking you.
If you've got a heavy enchantment build you can always try out Sphere of Safety as someone suggested above. Norn's Annex also taxes people to attack you and your Walkers, but in my experience, people usually just pay the life.
Maybe Flamebreak, though that'd be a good place to drop in a Plague Spitter if you were still planning on running it.
I hate exiling my own cards, So my vote would probably find a place for Endbringer before Dread Defiler, but I see how he can be quite the bomb if you have enough ammo for him.
Gren08- Just be aware that if you add in Repercussion with Breaker of Armies, you might die unless you can give it first/double strike. I do run an abnormally large amount of creatures, but they work well with Rakdos and a good amount of my deck's draw engines come from me grabbing dudes back from my graveyard into my hand.
Comic_Book_Joker- Ogre Battledriver > Cyclops of Eternal Fury? Do you play against Torpor Orb frequently in your meta? Just curious.
Also, Sire of Insanity put in an insane amount of work for me recently. He dealt with a player that kept buying back Constant Mists. It either baits out a removal spell that saves one of my fatties, or eats everyone's hand. With a Phyrexian Arena effect out, or an active Eye of Ugin, you take over a game pretty fast. I dropped Maga, Traitor to Mortals from my list for him- Maga can win games, but can only do so when Rakdos is out and doing his thing. Too often, Maga was sitting in my hand with that goofy look on his face making me whish he was anything else.
However, my group runs plenty of spot removal ever since I introduced them to Xenagos, God of Revels, so YMMV. If your group is prepared, they won't allow Maga Kills often. Warstorm Surge could work plenty well for a replacement, but I've won tons of games with that card and wanted to shake things up a bit.
So far, Sire of Insanity, Ugin, the Spirit Dragon and Void Winnower have been Prophet of Kruphix level power drops for me; You land them and the game turns into remove this permanent or die. I'm thinking of Playing Rakdos's Return, but I feel like the "target player" limitation might not be good enough for a multiplayer focused deck. Time will tell!
Repercussion is sick. Not only does no one block, but Red wraths turn into win conditions. Comic_Book_Joker, I could see Breaker of Armies doing so work to clear out tokens though.
Temur Battle Rage was never drawn.
Burnt Offering was fantastic and I will never go back to Talisman of Indulgence. My favorite play with it so far is Sac a titan for tons of mana to save my graveyard---> Graveyard shuffled into library---> activate Eye of Ugin with the mana to get the titan---> play the titan after combat for free.
I had replaced Flame Rift with Acidic Soil a while back to combat the many ramp decks in my metta. Even if you don't play many ramp decks, I'd tell you to go for the switch. For one additional mana you do a hell of a lot more damage late game, and let's be honest, you're not going to cast Flame Rift prior to t4 anyway without Rakdos out there.
As expected, Yawgmoth's Will let me win games I had no business winning. Scenario- I was just villainous wealthed for 14. They stole my Ugin, the Spirit Dragon, Chandra, Pyromaster and a bunch of fat Eldrazi. Top deck Yawgmoth's will... Acidic soil, Yawgmoth's will, Acidic Soil. "You just dealt me 32 damage", "Yeah, and I hit myself for 18. GG?"
High Market was a boss. It gained life, saved graveyards and made everything work better. Shizo, Death's Storehouse was good enough that I'm also ordering a Shinka, the Bloodsoaked Keep.
Sword of Light and Shadow was never drawn, but I can't imagine a case where I would have had it in my hand and not want to play it.
I may drop Animate Dead for Reanimate. The creature I Usually grab with Animate Dead is Rakdos, Lord of Riots, and he usually eats a naturalize at instant speed. Maybe I'll try and find room for both, but as it stands paying 4 life and a B for Rakdos looks pretty sweet.
I also managed to Cloudstone Curio Oblivion Sower until I exiled everyone's library. It was a cheesy, yet cool victory, but I wouldn't make too big of a habit of it. The only other enabler I see that you're missing from your deck is Plague Spitter. This little guy lets you hold back all your other enablers in your hand while he mows down x/1 creatures every upkeep. He also combos with Repercussion and Whip of Erebos.
Here's a link to my deck if you want to check it out. I run a few more creatures than most lists, but it works for me.
http://tappedout.net/mtg-decks/rakdos-time-to-riot/