This deck is my first foray into the world of Commander. I chose Ob Nixilis, Unshackled because of the buffs he gets from creature death, which happens A LOT in this deck. Also, he makes decks really regret fetching and other deck searches. Ghost Quarter can also really bone them if they aren't paying attention with Ob Nixilis, Unshackled. Since the day I saw Shadowborn Apostle when I first began playing, I've wanted to break the card. I feel like this deck is a good step to shattering it. There are some really good synergies in this deck. Pestilence Demon with Nykthos, Shrine to Nyx out can be a wincon, especially with a lot of high B costs out.
Reaper from the Abyss + Ob Nixilis, Unshackled + Sheoldred, Whispering One gets rid of a lot of creatures each turn and buffs Bob Nixon, Unpardoned quite a bit. It also works well with stuff like Harvester of Souls and Grim Haruspex
Another wincon is searching for Mortal Combat late game with Rune-Scarred Demon
1x Blood Artist
1x Bloodgift Demon
1x Crypt Ghast
1x Grim Haruspex
1x Harvester of Souls
1x Indulgent Tormentor
1x Lord of the Void
1x Overseer of the Damned
1x Pestilence Demon
1x Reaper from the Abyss
1x Rune-Scarred Demon
34x Shadowborn Apostle
1x Sheoldred, Whispering One
1x Xathrid Necromancer
1x Cabal Coffers
1x Evolving Wilds
1x Ghost Quarter
1x Nykthos, Shrine to Nyx
35x Swamp
1x Terramorphic Expanse
Instant (4)
1x Dark Ritual
1x Go for the Throat
1x Grip of Desolation
1x Malicious Affliction
1x Coat of Arms
1x Door of Destinies
1x Thrumming Stone
Enchantment (3)
1x Grave Pact
1x Mortal Combat
1x Phyrexian Arena
Sorcery (2)
1x Patriarch's Bidding
1x Read the Bones