Also Geralf's Messenger is worth it in this deck.

I'd still recommend Darksteel Ingot mainboard, or at least sideboard against Jund to avoid Putrefy . If sideboard, put it in place of Gravecrawler and mainboard those over Butcher Ghoul (which I recommend, anyway).

You also might want to remove a couple Doom Blade to fit in Murder .

Check out my Mono Black Control deck: Once you go black...

Consider adding Quag Sickness in either main or sideboard because it's normally a removal spell in mono black that can take out Indestructible and Regenerate creatures.

Barter in Blood is a good card, but it's better in low creature/creatureless black decks. You also have 0 card draw, you absolutely need some card draw in there and black has really good options. Sign in Blood is cheap and effective and can be used as a finisher if your opponent has 1-2 life and you can't get past blockers. Underworld Connections is basically a repeatable Sign in Blood . If you run 2-3 Corrupt then the life loss doesn't matter since you'll gain even more back.

I don't really understand why you're running Butcher Ghoul . He's a pretty bad card unless your using some sort of sacrifice mechanic to benefit yourself. Definitely not worth including just because you have Barter in Blood .

Finally, Liliana of the Veil is an incredible black card. Search library for a swamp every turn to gain +1 loyalty and make Corrupt stronger? Check. Pump creatures to kill opponent or kill a creature with -1/-1 counters? Yes please. Quadruple your mana base? Incredibly useful.

Wrong liliana Saljen you meant Liliana of the Dark Realms

Rakkhive - Yes, you're right, didn't bother to hover over the link before I hit submit. I was referencing Liliana of the Dark Realms .

Why Slitherhead ? Why not Gravecrawler or Underworld Connections or Duress ?

Its for the 2 mana drop demon so it doesn't come back for the opponents.

Cool deck. I like Shrivel a lot and Corrupt and Underworld Connections are all great mono-black cards. Mono-black is kind of exploding in my meta and guys are making top 8 with it and we have 60 people at the shop I play at, so it's very good. I think I would say that you need to play Grafdigger's Cage with Treacherous Pit-Dweller or that presents a problem for you, but you are playing other undying creatures so it doesn't seem to work that well. Maybe play Victim of Night instead as another solid 2-drop kill spell. I just think the pit-dweller is sketchy without the cage. Good build though. +1 from me

Ahh I remembered! Lifebane Zombie . I would play him over Treacherous Pit-Dweller solely for his intimidate, and many decks are playing either green or white, though you could always play him from sideboard if you don't want a wasted ability (though looking at the other player's hand is never bad).

Oh I see, if you scavenge a Slitherhead then it works well with Treacherous Pit-Dweller . I guess that works, haha, though it's still quite sketchy if you don't draw it, but you would probably know better than me.

What happens against control? I mean actual control with blue. I don't really see how this deck would work; all of your kill spells become dead draws.

Why the Archangel of Thune ? the AEtherling should be more than enough with the amount of Counters and removal. and that adds $80 bucks to the deck, for a card rotating out of standard in 2 months.

Archangel of Thune is actually rotating in 6 month (October). And it's quite an awesome sideboard plan, you should read up on it some more. You need to consider that when people play this deck, they typically sideout all their removal spells, especially Black decks. So, in response, you side in Archangel's to take advantage of that and catch them off guard and totally stomp them into the ground much faster than a lone Aetherling could. Also, the Archangel is essentially unbeatable for monoblue decks.