The goal of this deck is to get a control on the game with hapatra triggers killing dorks and/or stax creatures but also plays one sided cards like Karn, the Great Creator or Manglehorn with removal back up to play a non blue control game to buy time for tutoring out combos.
This deck does better in pods with a non creature deck that you can attack freely, but also needs other creature decks for fuel. My meta is very artifact based so there is quite a lot of removal here for that, feel free to change this for your meta but remember, as long as you have an open target your opponent's can't have x/1s creatures so creature removal isn't super needed, the only graveyard interaction is Faerie Macabre, my play group doesn't play a lot of graveyard decks so this is fine for regrowth targets but once again feel free to add more. The removal slots are really flexible and there is so much of it in golgari.
So these are all the combos of the deck so far:
(When I say snake I mean any creature you don't mind losing this can be tapped mana dorks)
Yawgmoth, Thran Physician
+
Hapatra, Vizier of Poisons
+
Moss Viper
=
Pay 1 life: Sacrifice your snake, put a counter on any creature (normally your opponents), draw a card, trigger, make a snake, sacrifice the snake, pay a life to repeat. This loop equals drawing cards equal to the total toughness of your opponent's creatures. So that is just Yawgmoth and hapatra this is where the fun begins.
You have heard of Yawgmoth's Bargain well hapatra and Yawgmoth have their own bargain.
Hapatra, Vizier of Poisons + Yawgmoth, Thran Physician
+ undying creature =
If you sacrifice the undying creature, put a counter on hapatra, this makes a snake, sacrificing the snake and putting a counter on the undying creature means now you can pay one life drawing a card this will also kill all of your opponent creatures with the other combo.
Yawgmoth, Thran Physician + Hapatra, Vizier of Poisons + Ivy Lane Denizen + Moss Viper =
This is the same outcome as before but slightly different -1/-1 and +1/+1 counter cancel out each other. So you can put a -1/-1 counter on something to make a snake then put a +1/+1 counter on that creature from the denizen trigger. So pay 1 life draw a card
Nest of Scarabs is another combo card, it's another Hapatra for when she costs too much to recast it will replace her in all but the denizen combos (denizen needs green creatures). but also goes "infinite" with Hapatra and Yawgmoth sacrificing one creature, and putting a counter on the other.
Now paying life to draw is good but that doesn't kill your opponent, you need to find a drain card like blood artists + Zulaport Cutthroat + Obelisk Spider (the spider can win though Leyline of the Void as it doesn't see death triggers). so with all the fast mana and tutors in the deck drawing 35 cards should win you the game you just have to hit moxen and one of those cards. Now you might be suspicious this combo is a lot of cards (3 outside the command zone) but remember just Yawgmoth and hapatra just drew you on average 4-15 cards that's normally enough to find a tutor or an undying creature. If it isn't you still killed all of your opponents creatures slowing them down, this is especially brutal for decks that need commanders like Urza, High Lord Artificer and Yuriko, the Tiger's Shadow because as long as this combo is in play they can't recast them, or you draw cards. but this also slows down decks that don't need their commander/s to work but use them as card advantage like Tymna the Weaver or Kraum, Ludevic's Opus.
Now time for some non Yawgmoth combos.
Devoted Druid is a really good mana dork in this deck, it can tap for 2 Mana on the turn you need on need it and make 2 snakes if you need more body's to sacrifice or a surprise block. But it also goes infinite with Hapatra, Vizier of Poisons
+
Ivy Lane Denizen
to make infinite snakes and infinite green mana. To do this combo the Druid does need to be able to tap (it doesn't if you don't need infinite mana) so when you untap the Druid you get a snake, this will trigger denizen and put a +1/+1 counter on druid. With infinite mana you can Finale of Devastation to give haste or Skullclamp to draw your deck or if worst comes to worst and you don't have the kill that turn you can pass and hope to untap, but it's Better to do this at end step because this combo is hard to see if it's in play, that being said it's the worst combo in this deck but it has won me games.
Now this is a black deck so the last combo is Bolas's Citadel + Sensei's Divining Top + Aetherflux Reservoir but there are some interesting cards for the combo in here, these are Doomsday and Weather the Storm.
Doomsday is in here for when you have Citadel and no other pieces if you have top in play or Aetherflux Reservoir tutor for the other one and win but if you have neither this is the pile: Aetherflux Reservoir + Sensei's Divining Top + * + * + Green Sun's Zenith.
The *'s can be removal for stax or protection like Veil of Summer (if it's Protection put it on top). if your life total is lower than 15 you need the top card to be Weather the Storm so you can cast Aetherflux Reservoir (you won't have enough life after you lose half rounded up). Now for the Green Sun's Zenith. this combo I haven't seen anyone do before so I want to get this out there for other Bolas's Citadel decks, so we all know that x is always 0 but it still shuffles in so if it's The last card in your deck you can keep playing it with Bolas's Citadel gaining infinite stormand infinite life with Aetherflux Reservoir
Now for Weather the Storm
So let's say you are going off with Sensei's Divining Top but you are running out of life, you have cast Sensei's Divining Top with Bolas's Citadel 30 times you are on 5 life but you hit this or Vampiric Tutor or Imperial Seal you are now on too low of a life total to cast Aetherflux Reservoir off the top, but if you tutor for Weather the Storm you can gain 90 life which is more than enough to cast the rest of your deck.
Necropotence is in here for value. It's a fair card in this deck if Bolas's Citadel isn't in play but when it is in play you can clear lands off the top so you can keep storming.
So that's all of the combos so far Yawgmoth is really busted now what are to pros of playing hapatra over Yawgmoth the main on is playing green, golgari is just mono black on steroids you get the mana dorks of green with the tutors of black plus golgari removal is the most efficient, the tutors are the most efficient and you get to play cards like Sylvan Library and Carpet of Flowers.
But Yawgmoth does have upside in the command zone. They can both remove problem creatures, but one draws cards. So when you play hapatra it's Easy to run out of gas and that's what kills this deck if you don't keep a hand with tutors or cards like Sylvan Library it's Easy to fall behind decks like Jhora, weatherlight captain or Tymna the Weaver, but that being said green adds so much to the Yawgmoth combos, in my opinion it's Worth Yawgmoth being in the 99 to be able to play green.
So here are some notable interactions
Strangleroot Geist + Young Wolf
with Skullclamp then attack with hapatra to reset the + counter
Wishclaw Talisman is mainly here as a 1 mana tutor the turn you try to go off but it can also get Karn, the Great Creator in a pinch so you opponents can't activate it
Eldritch Evolution is a card I realized was good when I was watching the modern deck that won an scg open, you can sacrifice Strangleroot Geist and get Yawgmoth, Thran Physician or sac snakes to get Geist.
Fetchlands are also creatures to start the chain with Yawgmoth and hapatra if you don't have a snake thanks to Dryad Arbor.
Forbidden Orchid is extremely good when your opponents don't play creature decks or there are no targets for hapatra to make snakes.
Activating Pendelhaven ability on a snake is super gross a ⅔ deathtouch creature can kill Tymna the Weaver among other things and still live.
Anyway I hope this was helpful, sorry if there are any spelling/ grammar mistakes this is my first primer so let me know how I did and if I missed anything, also if you play this deck and enjoy it let me know also feel free to ask questions.
Tip use Moss vipers as tokens especially if your name is Moss like me, the printing of moss viper is my favorite addition to the deck.
