doctorhydrogen

Lurking Predators would put a lot of dudes into play in this deck.

I'd run Whispersilk Cloak over Mask of Avacyn. It offers the same protection, but imo unblockable is worth a LOT more than measly +1/+2 especially since your dudes will likely be huge when they swing in.

Random stuff:

Greater Good is an absolute house in my version of this deck. Now, from the looks of this you're a little less fixated on +1/+1 counters than I am, but in my deck I routinely wind up with dudes with double-digit counters. I try to protect them as best I can, but inevitably someone is gonna get off a boardwipe or some removal I can't handle. It sucks losing a 12/12 . . . but it sucks a hell of a lot less when you can draw a dozen cards off it by sacrificing it in response. I can't stress enough how great the card is.

Recurring Insight costs 1 mana more than Jace's Ingenuity, and will probably draw you 10 more cards.

Wouldn't old-school Counterspell be radically better than Dash Hopes?

Corpsejack Menace is pretty great, as is Vorel of the Hull Clade and Gilder Bairn.

I'm running a sultai +1/+1 counter deck you can find here: http://www.mtgvault.com/doctorhydrogen/decks/the-mimeoplasm-edh-3/

I tried all three commanders you have listed in the sideboard. First up was Vorosh. He was . . . fine. Unexciting, but fine. I don't think I ever rolled him up more than once, and he generally died without impacting the board, but he was fine. He just didn't make plays, though. Because he didn't come into play with counters on him there wasn't a big splash when he hit because of Doubling Season or Corpsejack Menace.

Plan B was Damia. Damia is obviously a bomb. She's splashy. Problem is she needs to stick a turn to get you any draw, and since people kinda see her coming they tend to hold removal since nobody wants to see you draw six cards. But that just means she's strong. Still, the problem for me was the lack of anything to do with +1/+1 counters. I just felt too good-stuff and not on theme, which probably isn't an issue for like 99% of people, but it annoyed me.

Lastly I tried Mimeoplasm. I didn't want to use him, mostly because every Mimeoplasm deck I've seen is kinda douchey. Ramp, Buried Alive into Sheoldred, Vorinclex and It that Betrays, win target game. But I tried it. And it worked, fantastically. He comes into play with counters, so more often than not I get to double them right off the bat, and I almost always get to find something that's a toolbox without even really trying. I've won so many games just being able to cast him as a copy of something lame Sapphire Drake or Tuskguard Captain when everyone else thinks they are safe because I don't have flying or trample. The change made the deck so much more versatile.

Just something to consider from someone who has played a variant on this quite a bit.

Interesting, mine is enchantment-heavy, so really the only straight artifact removal I run is something like Vandablast that can be one-sided. Metas are funny like that. I also see a ton of indestructibles, so I run Sever the Bloodline and Ashes to Ashes in all my black decks, and Black Sun's Zenith is my go-to board wipe, where as some people would never run the first two and have Damnation as their primary. Funny how play-group changes so much.

Things to consider:

Obelisk of Naya: Chromatic Lantern has the same mana cost, provides the same mana AND it fixes your other lands if you're missing something or someone drops a Blood Moon or Magus of the Moon. Darksteel Ingot costs the same, provides the same mana, and is indestructible. Coalition Relic has the same cost, provides the same mana, and can get you two in a single turn if you need it. I'd run any over Obelisk, though imo in a three color deck Chromatic Lantern is heads and shoulders the best.

Armadillo Cloak: Loxodon Warhammer does the exact same thing for the exact same cost. Granted you have to equip it, but it won't get two-for-one'd so you can reuse it through wipes, removal, etc. Well worth it imo.

Ancient Grudge: Solid card, but imo I'd rather hit artifacts AND enchantments with something like Return to Dust or Decimate or Hull Breach.

I ran Olivia Vampires for awhile, so here are a few suggestions based on my experiences:

Chaos Warp: It's about your only way to deal with enchantments. Some guy with a Sphere of Safety or No Mercy or Asceticism is going to basically end the game for you otherwise. Worst case you can use it to tuck a general or some creature about to ruin your day. Personally I'd swap in Warp for Dark Ritual (amazing card in every other format, less great in multi-player commander).

Unstable Obelisk: It's a mana rock that late game you can also use as a way to take out an enchantment. Seriously, enchantments are an issue :) I'd run this over Vampire's Bite (which is pretty underwhelming, though certainly on theme which I do respect).

Arcane Lighthouse: You've got more than a few slots where you can run utility lands. Arcane Lighthouse will let you take hexproof or shrouded dudes with Olivia. I'd also consider Strip Mine, Nykthos Shrine to Nyx, and Flamekin Village. Also Graven Cairns, Shadowblood Ridge, Blackcleave Cliffs, Bloodfell Caves, and Sulfurous Springs are all sub-five dollar duals worth considering if you want to make sure you always have the right mana combo.

Ashes to Ashes/Sever the Bloodline: I'd slot one in over maybe Lightning Bolt. It's good to have a way to deal with indestructible dudes.

Blood Artists: Largely meta dependent, but I myself could never really get Stromkirk Noble to do much, but Blood Artist can deal a ton of damage. It's super painful to Prossh decks, and really punishes token decks on a boardwipe. Falkenrath Noble does the same thing, but it's a bit more expensive to cast.

Bile Blight: Again, largely a meta call here, but at least where I play Bile Blight would do a lot more work than Grasp of Darkness. Sure, it wouldn't kill 4/4's like Grasp, but you can use it to take out a token swarm or some critter and the clone someone else makes, etc.

Vandalblast: There's not a lot of times a lone Lightning Bolt is going to turn the tide, but destroying everyone else's artifacts can be a game-changer.

IMO any deck running Odric should run Infiltration Lens, because the only thing better saying "none of your eight dudes block" is saying "all eight of your dudes block my one chump wearing an Infiltration Lens, and I draw 16 cards."

Yeah, Marchesa is a beast. I actually took mine apart because it was just no fun to play against.

If Champion's Helm is primarily going to be used to protect your commander then I'd run Swiftfoot Boots instead. 4 to equip is a lot and you probably won't be able to equip the turn it comes into play, where as Boots cost 1 to equip which makes it a lot easier to get them on ASAP.

For me the problem was it becomes obvious that the deck kinda falls apart without Sherei, so people would just make sure to hold a removal spell. Athreos made that a lot harder, and it opened up some other really effective cards in white. HOWEVER you might not find youself having the issues I did depending on your meta, so it might be a non-ssue. I just thought I'd mention it as an option, as is Sekkuar, Deathkeeper.

One thing to at least ponder if you find yourself having problems with the deck is to change from Sherei to Athreos for the commander. You really don't need to alter much besides some lands to get white, and maybe slotting in Edgewalker and Remembrance, but at least for me I had a lot better luck once I made that move. Athreos is a lot harder to get rid of and works just as well IMO.

Every dude you have has flying, so Gravitational Shift would seem useful. You'd also draw a ton of cards with Bident of Thassa and Coastal Piracy and Dire Undercurrents.

Good call on Myriad Landscape, it's swamp ramp without losing swamps. I'm adding it now.

I'd much rather have Thespian's Stage or Vesuva to copy Cabal Coffers than Leechridden Swamp. Doing so has flat out ended games for me, where as Leechridden Swamp is just a slightly useful land. Expedition Map is fantastic to find Coffers (or a way to copy it) too.

Not sure if you've played this deck yet, but at some point I'd suggest testing Drana as commander instead of Anowon. My vamp tribal played much better after the swap. Anowon generates a ton of hate because people don't want to be forced to sacrifice creatures, and since he hits everyone you've got three or so other players ALL holding removal for him. Plus he has to actually sit a full round before he impacts the board, and literally in the dozen of games I played him he forced a sac maybe twice. Drana on the other hand generates less hate just by virtue not forcing sacrifices, and because she doesn't have an ability that hits the entire table she doesn't have every single person gunning for her. Plus you can pump mana into her from Black Market or Coffers. Just something to consider if you, like me, find out Anowon just didn't get it done.

IMO you're running too many creatures, especially in a deck that is probably going to be spending most of it's time swinging with one suited-up dude. I'd cut down to the low 20's.

Ancient Den, Darksteel Citadel and Great Furnance help you hit your Metalcraft threshhold.

Graveyard decks are also super vulnerable to simple anti-graveyard tech. All it takes is one Bojuka Bog (which every black deck could run) or a Leyline of the Void or Rest in Peace or Ground Seal or Grafdigger's Cage and you're effed in the bee. It's a strategy I tend tend to avoid in any established meta because if you're playing some of the same dudes week in and week out they can really easily adapt to your strategy with little effort (adding Bojuka Bog for example). Mimeoplasm also tends to draw hate because people assume you're going to be "cheating" stuff like Sheoldred into play either via your commander or Entomb/reanimate combos, and that tends to draw extra ire from players. I'm running Mimeo in my +1/+1 counters deck and he can draw aggro just by sitting in the command zone.

That said I'm going to guess you aren't planning on changing your deck's theme of graveyard shenanigans, so I'm going to just suggest some general card-for-card improvements.

Gild--->Sever the Bloodline: Sure it doesn't make you a chump blocker you can sac for mana, but it does let you wipe out a token swarm if you need it, and there's been times where I killed two different Nyleas and at least once where I took out Avacyn and two copies of her. Plus people forget you can flash it back, so it sits in your graveyard sneakily waiting for you to use it again.

Seek the Horizon--->Skyshroud Claim/Cultivate/Kodama's Reach/Rampant Growth: I'd much rather have my land fetch put something onto the board or it's not really ramp.

Go for the Throat--->Hero's Downfall: Good card, but I'd rather pay one mana more and be able to hit planeswalkers or a Blightsteel Colossus. I can't think of many times I'd wish the Hero's Downfall was a Go for the Throat, but I can imagine a ton of situations where I'd with the Go was a Downfall.

Brainstorm--->Recurring Insight: I do NOT like Brainstorm (or Brainstorm-like effects) in EDH. I think they're a trap. They're brutal in 60-card formats, and everyone assumes they're just as good here, but they're not, at least in my experience. You want cards that change the game, and while what is essentially a scry/cantrip effect can radically change the game in a 1v1 20-life format it's hardly ever going to do so in a multi-player 40 life format. Recurring Insight on the other hand can basically set up a flat-out win.

Dismiss into Dream--->Anything: Despite me just suggesting swapping a 1 mana card for a 6 mana card, I think your curve is goo high, and Dismiss is a good example. It's actually a sneakily great card in certain decks with a lot of built-in tap effects (Derevi for example) but here it's mostly a six mana way to discourage equipment. It's going to be a dead card 90% of the time, and you don't want 6 mana dead cards.

Market Festival--->Cultivate/Kodama's Reach: I run Market Festival in my Sigarda enchantress deck, but outside some enchantment theme it's just setting yourself up for someone to two-for-one you with a stripmine, and it goes away on any enchantment wipe like Nev Disk or Austere Command. Lands in play are much harder ramp to remove.

Find a slot for Cyclonic Rift. It wins games. So does Overwhelming Stampede.

Yep, especially in black/red as it gives another chance to sweep enchantments.

I'm also not a huge fan of the rituals. I guess they're fine in some kind of storm deck or a deck with Talrand/Young Pyromancer-type effects where the rituals also procc some other effect, but here I'm just not sure that a tiny bit of temporary ramp matters. Imagine a Hero's Downfall in the slot where Pyretic Ritual is for example; how many times are you gonna topdeck that ritual and think "oh thank $diety, now I have that one extra mana for one turn that I need to save this game!" vs. topdecking a Hero's Downfall with a Planeswalker about to ult or some scary-ass creature about to swing into your face for a gazillion life. The amount of times Pyretic Ritual changes the game is pretty infrequent, but that's not true of Downfall (or Terminate/Dreadbore, Nev Disk, Vandalblast, etc.)

I have to agree that Broodmother is an absolute house, especially in a tribal deck, but honestly in the grand scheme of things a complete lack of draw, no board wipes, and one single removal spell is a much larger issue than whether or not Dragon Broodmother is an upgrade over Rorix or whatever.

IMO if you're running a deck filled with beaters you need to find a slot for Homeward Path, or a theft deck can ruin your day.

I'm not sure it's worth the tempo hit with enter-the-battlefield-tapped lands like Rakdos Guildgate, Akoum Refuge, Bloodfell Caves, Evolving Wilds, and Terramorphic Expanse when options like Tainted Peaks, Graven Cairns, Dragonskull Summit, and Shadowblood Ridge exist and are all pretty cheap.

There's also not much downside to running Shizo Death's Storehouse and it might help your commander or another legendary dragon get through.

Strip Mine is relatively cheap, and you're bound to eventually find a Kor Haven or Maze of Ith or Vault of the Archangel or Gavony Township you want gone.

Mind Stone and Commander's Sphere are good, but I'd rather run Unstable Obelisk in one of those slots because aside from Chaos Warp you have no way to hit enchantments. It's saved my game more than once in my mono-black deck.

Cabal Coffers is so stupidly good that I'd run Expedition Map to find it or Vesuva/Stage to copy it if you already have it out.

Damnation is an amazing card, but I'm not sure I'd run it in mono black over Mutilate. Same CMC, and Mutilate will deal with indestructible dudes too. That might be a meta issue though, but I see so many indestructibles where I play that Mutilate and Black Sun's Zenith are my go-to wipes.

Have you had any luck with Temporal Extortion? For me, early game when nobody would pay the life cost the extra turn usually just wound up being a land drop and a card draw, maybe one attack. Late game when an extra turn can be devestating people wind up just paying it and their life totals are low enough that it really doesn't make much difference. It's a cool card in theory, but at least for me in execution it just never paid off. I wound up replacing it with Imp's Mischief, which HAS been a bomb. Turning someone's targeted removal back to them can be a huge swing, especially because nobody expects it in black.

Underworld Connections costs 3 to cast, and it essentially costs B to activate (since it's on a land you can't then use) and 1 life to get one card. Greed costs 4 to cast, and it also costs B to activate and 1 life to get a card, so it's the same payment for a card. Greed however can be used multiple times a turn, and it can't be 2-for-1'ed by someone Strip Mine'ing the land. One single mana for in the casting cost to have the option to draw multiple cards per turn if you want and not be vulnerable to a 2-for-1 seems well worth the extra cost. Necropotence is better than either, IMO, but Greed is easier to get.

Unstable Obelisk makes for a really solid mana rock in mono-black since it gives you a way to deal with artifacts or enchantments if need be besides just hoping you have Karn out.