Mono Black Legacy

I love the idea that monoblack can compete in legacy.

Some of the problems I see in here are as follows:

-problem- the 16 discard sorceries basically guarantee a turn 1 or 2 (or both) discard, which tempos the opponent nicely, but after that they (discard cards) run out of steam quickly. Topdecking them in the middle game and onward is borderline useless, especially since opponent can play instants in response, and in game 2 and 3 opponent can change playstyle considerable to sluice cards onto the field and keep a blank hand or a hand with only instants, effectively murdering 16 of your cards (20 if you count the specters) which is a huge problem.

-solution- one thing that helps tremendously ive found as an outlet for "overtaxed" discard outlets is pack rat, which turns the useless discard cards into win conditions (note, fixes your useless land problem as well), so if you have one it doesn't really matter what you draw

-problem- 4 dark rituals is risky- yes, it gives you a possible turn 1 specter, or turn 1 thoughtseize and hymn, but the advantage there isn't as big as it at first seems. Turn 1 specter uses 2 of your cards to accelerate and takes a turn to take a card away from opponent, so in order to get card advantage from it you have to actually cycle through another turn, giving opponent +1 card to respond to it and a whole other turn before you actually get ahead on the combo (using the dark ritual puts you at -1, so you have to hit with specter twice to be +1), which really gives opponent 2 turns to respond to gain equality (note, 1 drop answers to specter are run in legacy all day long- path, bolt, fatal push, etc). Turn 1 thoughtseize and hymn runs into similar, albeit less worrisome, problems, as it takes 3 of your cards to make opponent discard 3 of his, putting you at +0 with a targeted discard and the chance to rob opponent of lands. That being said, the rob lands factor is high, especially if you drop thoughtseize first, so this option is much better, but it requires 3 cards to group together, which is slim in an opening.
4 rituals also allows you to do a turn 2 obliterator, which is lovely of course, but you run into the same +/- problems as above, in that you will be at -1 and opponent will either have +2 or 3 cards to respond to negate the combo, meaning that he will have 9 or 10 cards (1/6 of his deck) to undo the threat before it even starts rolling, making it less valuable as a credible threat.
On top of all of this, once you get past turn 4 or 5 ish, its a complete dead draw as this deck's curve is minimal and tombstalker is gunna have no problem delving. Which brings your decks possible dead draw total to 20 (discard and ritual becoming less useful/useless once both players are out of the opening).

-solution- pack rat helps to fix this for the same reasons as above, but honestly I wouldn't even bother running it, especially with the tendency for legacy to feature endless counter stuff without paying a mana cost effects like force of will, which will nuke your chances. Yes, it is gunna take away your turn 1 madness, but since youre running currently 12 turn 1 discard options (virtually guaranteeing you will have one in the opening hand), you retain significant tempo to start the game anyway, so fixing the possible dead draw/card advantage problems by dropping it is worth considering.

-problem- your curve is actually slightly off. You're currently running only 8 2-drops, but its actually lower because malakir wants to be a 3 drop (although can function without it if necessary), so really you only have hymn to play turn 2, which cuts down on the decks tempo gaining greatly (this holds true even if you keep the rituals because you will use them turn 1). In addition, your creature base is heavily 3 drops and up, meaning youre giving opponent time to recover from your turn 1/2 discard before you are actually up and running on a win condition, which is a problem.

-solution- consider swapping out specter or nighthawk (or both) for gifted aetherborn/dark confidant/bitterblossom. Yes, confidant and blossom cost a pretty penny, so that might not be an option, but aetherborn still goes for cheap and is a faster and realistically more useful card in your deck than nighthawk because you can drop it turn 2 and start the clock a runnin, and in legacy the lack of flying will be less worrysome.

-problem- your curve is low enough to be ok with 20 lands, especially if you swap into some of the suggestions above, but I would want to see at least a few more fetch lands to really grind the consistency of this deck into gear. Again, they are a touch expensive, so no worries if its not an option.

-solution- optional

-problem- you barely have any direct interaction for boardstate, which is ok because youre trying to stop it with discard, but if opponent slips anything by you its gunna be hard to deal with

-solution- swapping out rituals and cutting into the 3 drops for 2 drops will speed the deck up/make it more consistent which should minimize this potential badness.

Just my thoughs