Update 3/29/21: Took out Syr Konrad and Black Market for Vampiric Tutor and Feed the Swarm. Considered cutting Phyrexian Arena instead of Market. Syr Konrad is redundant to other pingers in the deck and the goal is to go infinite, not slowly chip opponents down; for that purpose his CMC is too high. With Market, you basically have to play it for 5, kill creatures, keep it on board, then untap--a little too slow for what this deck is trying to do. It is an autowin when you untap with it though. 

I've been playing this deck a lot lately. It's insane. If you have 5 mana you can go for the win at any time. Don't be afraid to draw deep through your deck to find the pieces you are missing! Often I will go down to 1-5 life to put the pieces together.  

Combo version of Yawgmoth. This is technically a casual deck, but fairly powered up; I've played it with my cEDH group and the deck can hang with them, but doesn't quite pop off for turn 2-5 wins like the Ad Nauseaum cEDH version. As a word of caution, it's nice to warn your opponents that this is a powered up deck. Playing it at a table with 5-6 power level decks won't make you any friends. 

There are 2 basic paths to winning. The first method is to use Yawgmoth to dig deep into the deck and eventually have an infinite sacrifice loop with a damage enabler such as Blood Artist or Zulaport Cutthroat to burn the entire table down. There's a nice explanation of how to do this here https://tappedout.net/mtg-decks/yawgs-win-cedh/ 

The second path is to make make big mana to set up an end-game payoff. This can use a sacrifice loop with Pitiless Plunderer, Phyrexian Altar or Black Market to make the mana. Then cast Torment of Hailfire or cast Ichor Rats and use Yawgmoth to proliferate with 18 black mana to kill the table. 

I recommend including at least 1 backup strategy. In this deck, I cheat Mikaeus into play using tools such as Animate Dead, Reanimate or Victimize and then get Triskelion on board for an infinite damage loop (a nice explanation on this here https://www.youtube.com/watch?v=2BXXZBWrTfk). If you can get both of them into the graveyard--which isn't hard using Entomb or Yawgmoth's discard ability--you can play Victimize for a mere 3 mana to get them both onto the board. If you prefer, you can add Aetherflux Reservoir and Sensei's Divining Top with Bolas's Citadel to do essentially the same thing; this is described in the first link above.

Enjoy!