Snow-Covered Swamp instead of regular swamps. Makes you more greedy with Extraplanar Lens .

I don't know. Can it really be a suicide deck without Pox ? Interesting. I really don't remember the creature you're playing as a general, and I have been playing for a long time. What a sick creature to choose as a general. You're a bad person. Cool commander! Cool deck!

Pox is good. I'm also a fan of Death Cloud .

There's an unwritten rule in my playgroup that basically states that I'm not allowed to play Death Cloud ...Long story.

They let you play Smokestack and Braids, Cabal Minion , but not Death Cloud ? Man, you must've really pissed them off!

Haha... Yeah. Luckily smokestack and braids weren't in the games where deathcloud was involved.

Corrupt * drops mic *

that seems far over costed for the effect.

still amazing for any MB deck

Why Reanimate and company? Isn't that what Chainer, Dementia Master is for? Instead of Rise of the Dark Realms , you could consider Morality Shift .
Oh, dude... Black Cat .
It seems like making creatures is important for this deck. Abhorrent Overlord can be pretty good at that. Endrek Sahr, Master Breeder might be good, too.
Check out Extractor Demon . Triggers when anyone's creatures die, and mills dudes to anyone's yard.
Graveborn Muse is just god card draw that can be sacrificed and returned as needed.
You could also try Skirge Familiar . I've been very happy with it in my Balthor the Defiler deck. Bog Witch performs the same role(s) more or less effectively. Any card is a Dark Ritual is pretty nice.
Mikaeus, the Unhallowed might also be good.
Have you considered Delirium Skeins or Noxious Vapors ?
Vengeful Pharaoh could also be worth a go. It works really well with Extractor Demon .
If you're looking to repeat ETB, then Liliana's Specter , Cackling Fiend , and Mogis's Marauder seem strong. Also, Earsplitting Rats . I was giddy when I found that one.
Slum Reaper is another Fleshbag Marauder .Doom Blade definitely needs to be a Bone Shredder . By the same token, Slaughter Pact could be Shriekmaw .
Faceless Butcher is also solid removal, but perhaps not what your deck is looking for.
I don't like Spawning Pit or Trading Post as sac outlets. You could be casting Carrion Feeder or Chaining a Devouring Strossus . All while increasing your creature count AND devotion.

Oh, how I wish we could edit comments. Balthor the Defiled is the deck, not the defiler.

Also, Kuro, Pitlord seems solid for this deck. It looks pretty bad at first glance, but killing dudes at instant speed for 0 mana is pret-ty strong.

All interesting suggestions. I'm not going to comment on each card individually but I may end up considering/keeping some.

Undead Gladiator - Draw cards and pitches creatures for Chainer to reanimate. Not the world's most mana-efficient way of doing either but it's versatile and card-efficient and you have plenty of mana in mono-black.

Skullclamp - Great little card drawing engine. Plays well with sac outlets like Altars and Stax, weenies like Nether Traitor and the snakes from Ophiomancer, and creatures that just aren't long for the world like Kokusho and Mindslicer.

Baleful Force - Roided up Phyrexian Arena on a giant threatening stick. Good draw engine to cheat out with Chainer.

Corpse Connoisseur - Reusable Entomb. Again, it's a little mana-intense, but it's another body to sacrifice and once it's in the graveyard Chainer can use him again.

Whip of Erebos - Giving all your pumped up Nightmares Lifelink and swinging is a good way to reload your life total. Don't discount the haste either, it might give you that edge you need late in the game.

Crypt Ghast can't be played because it has W in its colour identity - sorry.

Looking pretty good other than that - takes a whole different approach than my Chainer EDH.

Crypt Ghast can be played. The W isn't a part of it's color identity since it's in reminder text.

Trust me, I've looked into this. So unless it changed very recently, I'm certain that I'm right.

For a more specific ruling, see rule 903.4b

Mindslicer + Waste Not I laughed.. so much.

I know...hilarity ensued when I actually pulled that combo. Though, I'm not sure about keeping Waste Not in the deck...not enough discard currently...may change that up though.

Grave Pact should replace Dictate of Erebos . The mana cost difference tends to be relevant.

Kagemaro, First to Suffer and Reiver Demon could very well replace two of your mass removal sorceries. Both can be revived whenever you need mass removal. Dregs of Sorrow is also interesting, adding to EDH's diplomacy. Oh! And Mutilate . I prefer any of those to your Toxic Deluge which might hurt you quite a bit since you're already playing a commander that hurts you quite a bit.

Syphon Flesh might also be interesting here, giving you several tokens.

Feel free to take a look at my own take to this awesome commander: Chainer Commander

You might consider up-ing yout tutor count, Increasing Ambition is good value for money and flashback is nice. Also, Demonic Collusion could be good for pitching creatures. Champion of Stray Souls may also fit your build.

I agree with the Grave Pact replacement...though I don't currently have one...hence the substitution. The replacements for mass removal won't work as well because I tend to avoid casting creatures from hand if possible and my hand very rarely is actually full.

I'm not running many tutors just because my groups frowns on them a bit because they tend to drag out the game longer than it really needs to go.

Just make sure if you ever play twin headed giant to swap back out your Grave Pact for Dictate of Erebos :P