As a 8Rack player (Mono black), I kinda like your idea to splash Green, but I feel like your deck is something less powerful than Jund.
My problem is, you don't have that much discard and don' take every advantage of your green splash.
You'll play Bob on turn 2, maybe. But you don't want to play
Augur of Skulls or
Liliana's Caress. Your aim seems to discard them as much as possible to get rid of their answers to your threats.
You have only 10 discards cards, with Liliana, that's not what we can call a discard deck. Mono black discard plays 22 cards to discards (including
Smallpox)
To keep your main idea, there are some changes I'd make :
-4
Augur of Skulls-3
Liliana's Caress-3
Nyxathid-2
Swamp+4
Wrench Mind (More discard)
+1
Inquisition of Kozilek (More discard)
+2
Shrieking Affliction (More rack's damages, Rack >
Liliana's Caress)
+3
Scavenging Ooze (Will have a lot of fuel, helps with the life loss of Bob, also strong against Delver's deck)
+1
Twilight Mire+1
Urborg, Tomb of Yawgmoth (Specially with Liliana and
Wrench mind, you want your two Black on turn 2, maybe considering 2, also your fetchs are
Swamp,at some point of the game you don't need to lose life for fetching)
Ofc, more Liliana's would be great, but considering it's bit expensive, I think you don't have them and stick to your list, I would consider swaping 1 or 2 Bob for
Tasigur, the Golden fang.
By splashing Green, i'd play some kind of "Loam Discard", with
Life from the Loam for infinite discard,
Darkblast,
Vengeful Pharaoh even
Smallpox can be considering.
Hopefuly that's helped.