I would cut some of the creature removal in your sideboard for at least 3 Duress. There are a few decks out there where creature removal is dead, and you want to be able to replace all of the creature removal in your mainboard for live cards.

Yeah I was debating about that or not. I'll probably replace the Geth's Verdict and 1 Bile Blight for the Duress.

I am a total fan of black myself and playing it in some capacity. I would suggest Cruel Edict and Hymn to Tourach which could be fun.

Its a modern deck so sadly i can't use Hymn to Tourach and i was thinking about adding Geth's Verdict to the side board. Thank you for commenting!

Lashwrithe is on of my favorite mono-black cards. It can be very big As you accumulate lands over time, and equipping it to something with lifelink can seal the game.

Fireshrieker is one of my favorite cards, then you mix it with Nightmare Lash or Strata Scythe

Surprised no Nykthos, Shrine to Nyx.

I don't feel as if i really need it or could even run it. While my creatures are very high in devoution i don't run many.

I think the major problem I have with the deck is its lack of card draw. You need Night's Whisper, Dark Confidant, Phyrexian Arena, something. Apart from that... I'd swap Wrench Mind for Inquisition of Kozilek, and I'd like to see a few Dismember in your sideboard to deal with the likes of Infect and Affinity. Otherwise, it looks solid. I hope no one in your meta takes a liking to Ensnaring Bridge.

I already have Inquisition of Kozilek and i was thinking about replacing Wrench Mind with either Dark Confidant or Phyrexian Arena, but i'm woried about Dark Confidant killing me due to the higher drops and Phyrexian Arena rasing my curve.

Not sure how I missed Inquisition of Kozilek already being there, lol. I know Phyrexian Arena ups your curve a bit, but I think it's worth it - you have plenty of T2 plays already, and that would really get you settled.

Ok i'll give it a try when i can get them. How many do you think i should run and what should i replace?

I would say 2-3, and I'd probably axe the Wrench Mind. Given that you have 4 Inquisition of Kozilek and 4 Thoughtseize, I think your discard game is on point. Wrench Mind and Phyrexian Arena have the same purpose in mind (getting you card advantage over your opponent), but the Arena is less conditional (since their discarding an artifact leaves you at card parity), less redundant (which in this case is a good thing), and more reusable.

Ok i'll try it. Also why Dismember for affinity? I normally use Bile Blight

It depends on whether they run Master of Etherium or not. If they do, Dismember oftentimes catches the big guy.

Spellskite? Gurmag Angler?

As APPLE01DOJ points out, another perk of Dismember is that it has game against pretty much any Modern deck with big, tough creatures. Gurmag Angler, Tasigur, the Golden Fang, Siege Rhino, Spellskite, Restoration Angel... none of them survive a Dismember to the chin.

Ok i'll have to give it a try. I will probably pull Bile Blight for it So far Phyrexian Arena has been great. As far as Gurmag Angler goes i tried it, but i prefer Phyrexian Obliterator. Thanks for the suggestions guys!

Personally I don't like Murderous Cut in a deck without fetch lands Victim of Night is a pretty underrated substitute. It gets pretty much everything the big decks run at 2 cmc. I bring it up mainly because of affinity and tron, because you can't Go for the Throat anything from affinity, and you can't Go for the Throat or Dismember a Wurmcoil Engine, but you can use Victim of Night on almost anything. The downside being that it costs 2 black but since you're running mono black that seems okay. Otherwise fetch lands fuel Murderous Cut as well as do good things for Bloodghast, but I really dont think you need the extra loss of life and they may thin your deck, but you have draw power so eh...

Well i am still working on the removal package of the deck, but i have had pretty good luck with Murderous Cut so far. I do like Victim of Night and have used it before. I'm not sure if i like it more then Go for the Throat

I tried Dismember, but i did not like the life lose from it for having a one drop removal spell. So i am giving Victim of Night and Tragic Slip a try. Any other suggestions on removal if Tragic Slip does not work?

Grasp of Darkness is pretty okay. It's completely nondiscriminatory and its -4/-4 will still get most threats, but it's still risky against big creature decks. Personally I think Victim of Night is your best shot

if you're looking specifically for a 1 drop there's Stabbing Pain, Midnight Charm, and Disfigure. Since tragic slip needs morbid to work well one of these might be a better 1 drop, and the first 2 have a little more utility. There's also Vendetta but we've already discussed color shutouts and life loss

Darkblast is a thing.

Ok i will give them some thought. I'm not really opposed to running all 2 drop removal spells so play around with a few.