Yawgmoth, Thran Physician - Proactive Control (EDH / Commander)

This Yawgmoth build aims at building up a mono black control/stax prison for our opponents in early-mid-game (turn 3-5) and win by comboing off in mid-late-game (turn 5-7) but it's also easy possible to combo off on turn 4.
We want to ramp into cards like Oppression or Mindslicer or card combinations like Bitterblossom/Dreadhorde Invasion/Ophiomancer/Reassembling Skeleton and Contamination to slow down our opponents.

Combo:

Butcher Ghoul or Geralf's Messenger + another Undying Creature + Yawgmoth, Thran Physician + Blood Artist or Zulaport Cutthroat
This also works with Mikaeus, the Unhallowed and two random non-human creatures.
-> Draw whole deck and kill opponents due to loss of life

Mikaeus, the Unhallowed + Pawn of Ulamog or Weaponcraft Enthusiast or Carrier Thrall + Yawgmoth, Thran Physician + Blood Artist or Zulaport Cutthroat
-> same effect

Undying Creature + Pawn of Ulamog or Bridge from Below or Desecrated Tomb or Genesis Chamber or Nest of Scarabs(and one more creature on the battlefield) + Yawgmoth, Thran Physician + Blood Artist or Zulaport Cutthroat
-> same effect

Geralf's Messenger + another Undying Creature or one of the 5 substitutes + Yawgmoth, Thran Physician + Deathgreeter
-> same effect

Backup Plans:

Mikaeus, the Unhallowed + Walking Ballista + Viscera Seer or Carrion Feeder
-> Infinite damage
If Yawgmoth, Thran Physician is your sac outlet you will draw your deck this way, paying one life per card until you find Viscera Seer or Carrion Feeder.

Yawgmoth, Thran Physician + Liliana, Dreadhorde General
-> 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)