Mono-Black discard for modern, currently I'm playing a budget version of the deck but this is what I want to head towards. I've seen many versions of this deck running around but this is what I like best, all feedback is greatly appreciated. If you're confused about how anything works or just have a general question, leave a comment.
Win Cons
The Rack - This is where it all begins. This card drains away at our opponents life total, putting them on a surprisingly fast clock. If they have 2 cards in hand at upkeep, they take 1 damage, if they have 1 card at upkeep, they take 2 damage, and if they have no cards in hand at upkeep, they take a whopping 3 damage. This damage stacks up quickly and multiple racks get the job done insanely fast (Note: This damage can be redirected to planeswalkers).
Shrieking Affliction - Our game plan would be fairly weak with only a 4 of win con; conveniently, this card is essentially the same thing, but says that if an opponent has 1 or fewer cards in hand, they lose 3 life.
Discard Spells
Inquisition of Kozilek - Targeted discard spell that allows you to see all of the information in an opponents hand and strip a low cmc card from their hand. I prefer to cast this card early, or even first from your hand to stop early plays that your opponents will make.
Raven's Crime - One of the most important discard spells in the deck. At first glance, it may seem like extra fluff but with Dakmor Salvage you can create a recurring discard engine in the right board state where you are already in control of the game.
Thoughtseize - All around great discard spell, it's an allstar staple in multiple formats and can be a great early to mid game discard spell to cast, allowing us to receive information, and disrupt our opponents future plays.
Wrench Mind - A slightly more hefty discard spell that is always a great turn two cast. I prefer to cast it on turn two because its one card for two discards, rather than blowing an Inquisition of Kozilek and Thoughtseize in the same turn, allowing us to save these spells for mid game.
Other Spells
Bile Blight - In my local game stores meta, there is a lot of the modern event deck running around. This deck gives me an insane amount of trouble, and so I needed an answer for these decks. A friend recommended Bile Blight and I saw its use against token decks being very strong, and it can also be very handy removal against a lot of other decks too, giving it a home in the main deck with an additional copy in sideboard.
Victim of Night - An all around strong targeted removal spell. Although it does not hit Zombies, Werewolves, or Vampires, 94% of the time this is not an issue.
Ensnaring Bridge - This card is a great lock down against any decks that are trying to beat us down with creatures. We can consistently keep our hand clean, allowing our opponents to get no attacks through.
Liliana of the Veil - What isn't there to like about Liliana, she's a cool-ass planeswalker, has three awesome, relevant abilities, and is so satisfying to play on turn three. Liliana gives us constant discard every turn, and most of the time us dropping a card isn't relevant anyways, and she can also come down to relieve board pressure if there is one pesky creature on the opponents table.
Waste Not - This is my favorite card in the deck. Originally, before this card was spoiled, I was playing 8rack but it just felt like it was missing some ingenuity. When Waste Not was spoiled, I immediately started play testing with the card and I loved it. It gives us so much utility and can help with so many aspects of the game. It forces our opponents to discard bearing in mind the benefits that we will receive, rather than according to their game plan, forcing opponents to play around us. Having two of these cards on board at the same time can be ridiculous, adding four black to our mana pool, getting two zombie tokens, or even just drawing to cards is huge for this deck and it gives us advantages to the strategy we are already intending on using.