VampiricJace those suggestions did help a lot, as you can see many of your suggestions were taken into account, so thanks so much for the help. If you still have any other suggestions they would be equally appreciated.

I really like the hand disruption (+1 from me, btw) because it can really dick up their plays from the beginning. Do you have room for a Mind Shatter in there? that much mana being kicked out, on 5 if you have a Crypt Ghast you could easily strip whatever remains of their hand, then power up a huge Exsanguinate.

Oh and reading a post from further up, i just wanted to clarify that if you sac Korlash, you can't use his regen ability, it only works to keep him from being destroyed (from lethal damage or destroy effects), and sacrifice is a different effect.

abdulbaqr, thanks for the clarification, also Hymn to Tourach is nearly perfectly on curve and useful at all time without draining you mana pool like Mind Shatter. Though I like the card, I don't think it will fit because of how mana intensive it is to play. But thanks for the upvote, card suggestion, and rules clarification. That difference is kinda important to know.

Also I preordered a box of MMA 2015 so I hope to crack an Emrakul and put another one in here. I think hardcasting Emrakul is better than discarding someone's hand late game (which is when I would use Mind Shatter because of how mana intensive it is). If only Mind Twist was legal in legacy right?

@Coinman1863, I have only one question, why pick me to help with your deck?

First if all I'd find cards that are good against the top played decks in legacy right now on mtgtop8.com and see what mono-black cards are good in the legacy format, and/or against the meta in your town but legacy format usually puts out the most efficient work (this may take a little bit of deck studying). Second of all. I'd run a straight play-set of Thoughtseize instead of Duress, or find room to run a play-set of both. As long as you get your card knowledge, and hopefully some card advantage in as well. You also get a turn one F*** you! You're going to regret keeping that "good hand".

My advice to you would be asking yourself this: "How am I going to deal with these top played decks?" Such as how am I going to play against Show and Tell, Delver, etc. because hard-casting something may never do the trick, there's high potential of the spell getting countered, especially Force of Will, or Daze if you don't play around it correctly. This deck is pretty solid, may be kinda slow but it's cool.

I hope you may find the information a bit helpful.

FALLEN-X-ANGEL you seemed to have a lot of experience on the competitive scene, I may have been playing for longer but I have little to no experience playing competitively, almost exclusively casual decks.

Thanks for the suggestions and the complement. Do you have any idea as to what to cut besides the Duresses? I need to cut one more card to fit in the playset.

Also does anyone have thoughts on 2 Phyrexian Obliterator to replace the two Tendrils of Corruption?

@Coinman1863, I'd probably take out the Diabolic Tutors. If not that then Maybe Tendrils of Corruption. In addition the Phyrexian Obliterator would be a great addition in replacement of the Tendrils of Corruption.