[cEDH] Yawgmoth's undying engine (EDH / Commander) [Révision 126]

This Yawgmoth build aims at building up a mono black control prison for our opponents in early-mid-game (turn 3-4) if we have no option to combo that early and wins turn 4-6 most of the time.

Prison:

Shut down aggro- or other creature-based decks with Yawgmoth, Thran Physician + creatures or Grave Pact or Nest of Scarabs + Yawgmoth, Thran Physician
Shut down opponent's non-black Lands with Contamination
Shut down graveyard-decks with Leyline of the Void
Shut down enemy commanders, combo pieces or ramp with Phyrexian Revoker
Slow down/Shut down artifact-based decks with Gate to Phyrexia or Karn, the Great Creator
Slow or shut down combo-decks with Praetor's Grasp
Control your opponent's hands with Duress or Mind Twist

What to tutor for?

Regular tutors will find answers and hate pieces, power ramp like Sol Ring/Ancient Tomb or carddraw with Necropotence in early game
Entomb will find Bloodghast for a static carddraw and board control engine with your Commander, Bridge from Below to assemble your Undying combo
Insidious Dreams will put Aetherflux Reservoir, Sensei's Divining Top and Bolas's Citadel on top of your library in this order.
If you already control Sensei's Divining Top or Bolas's Citadel it's always a good idea to tutor for the corresponding other.
If you already control Bolas's Citadel or Necropotence it's always a good idea to tutor for the corresponding other.

Win Conditions:

Butcher Ghoul, Geralf's Messenger, Sightless Ghoul or Evernight Shade + another Undying Creature + Yawgmoth, Thran Physician + Zulaport Cutthroat or Bastion of Remembrance
-> Draw whole deck and kill opponents due to loss of life (with 40 or more cards in your library)

Undying Creature + Pawn of Ulamog or Bridge from Below in Graveyard or Nest of Scarabs(and one more creature on the battlefield) + Yawgmoth, Thran Physician + Zulaport Cutthroat or Bastion of Remembrance
-> same effect

Geralf's Messenger + another Undying Creature or one of the 3 substitutes + Yawgmoth, Thran Physician + Deathgreeter
-> same effect (with 60 or more cards in your library)

Note: In the current build this combo doesn't go infinite because Yawg's draw isn't a may effect. If people in your playgroup use lifegain you can include Elixir of Immortality to chain fast mana like Lotus Petal + Dark Ritual to cast and activate Elixir to refill your library and go infinite

Backup Plans:
Enchantments like Rest in Peace, Leyline of the Void or Sulfuric Vortex are the worst nightmares of this deck. Answering opponent's enchantments is this decks biggest problem in gernal. Cause black has nothing useful to offer we run Ratchet Bomb and Blast Zone
Therefore we need ways to win without abusing aristocrat and graveyard strategies...

Bolas's Citadel + Aetherflux Reservoir + Sensei's Divining Top
-> Repeatedly use Sensei's Divining Top activated ability to put it on top of your library and cast it for one life with Bolas's Citadel triggering Aetherflux Reservoir each time. Then use Aetherflux Reservoirs activated ability 3 times.
-> Most of the time you can start comboing off with just Citadel and Top paying one life per card till you run into Aetherflux or created enough value
-> You can use Insidious Dreams in your opponent's end step if you have 3 more cards in hand and 6 mana available in your turn to win out of nowhere

Yawgmoth, Thran Physician + Liliana, Dreadhorde General
-> -9 Liliana for massive permanent destruction
-> In the worst case you'll have to pay 12 mana to cast Liliana and proliferate the loyalty counters 3 times with Yawgmoth in the same turn (You can use K'rrik, Son of Yawgmoth to pay life instead).

Upgrades: Mana Crypt, Mox Diamond, Thoughtseize, (Scroll Rack), Imperial Seal, Dark Confidant, Lake of the Dead, Gemstone Caverns, Volrath's Stronghold, Cavern of Souls

Things I might change if money wouldn't matter:

5 Snow-Covered Swamp <-> Lake of the Dead, Gemstone Caverns, Volrath's Stronghold, Cavern of Souls, Mox Diamond

Duress <-> Thoughtseize

Night's Whisper <-> Dark Confidant

Grave Pact <-> Mana Crypt

Weaponcraft Enthusiast <-> Imperial Seal