Korvold, Fae-Cursed King
Approximate Total Cost:
Win Conditions
Swing with the King
The first is rather obvious - Korvold can get pretty big pretty quick. A decent turn could see him hit 11 power and get the ability to finish someone off in a couple of attacks, and a really great turn could see him hit 21 power and just one-shot someone, too.
All the King's horses and all the King's men
Pathbreaker Ibex is the other option, given the potential for creatures to have haste and with the token production this deck is capable of it's not too difficult to have a small army of tokens get big enough to trample over half the table. Because Korvold effectively starts out as a 5/5 once he hits the board (due to having to sacrifice a permanent on ETB) the Ibex's buff will at least be 5 power, but in all likelihood it will be more than that depending on how far the game has developed.
Just Golgari Things
There's a line with Protean Hulk that makes finding and looping Gray Merchant twice fairly easy:
1) Get the Hulk out and sacrifice him
2) Fetch Carrion Feeder/Viscera Seer + Phyrexian Delver
3) Return the Hulk with the Delver, sacrifice the Hulk again
4) Fetch Mikaeus, the Unhallowed
5) Sacrifice Phyrexian Delver, it'll return with a +1/+1 counter due to Mikaeus and we can bring back the Hulk again
6) Sacrifice the Hulk again, this time finding Gray Merchant + an arbitrary 1 drop
We'll be able to use the Gray Merchant twice, once on initial entry and another time because of Mikaeus's Undying trigger. Usually it'll drain for 8-12 both times - gaining back all the life lost from the Delver and then some, plus reducing opponent's life totals substantially.
That said, it's easy enough to use Protean Hulk to find almost any combinations of things. I foresee World Shaper + Lotus Cobra and one of the land animators (Natural Affinity or Life) being a favorite line to generate big mana.
Flashy Finish
Lastly, Thermopod + Sneak Attack + Korvold out will allow us to sacrifice creatures for using Thermopod to Sneak out more creatures to sacrifice, potentially drawing through a lot of the deck and repeating the process. We'll eventually stumble on some combination of Gray Merchant/Mayhem Devil/Pathbreaker to close the game out.
One thing I do think the list lacks and that I'm going to try and find space for is something like Cut//Ribbons. Because of all the mana this list can generate I definitely want access to at least one mana sink and this one seems perfect. The first half can remove a creature early in the game, and later on when I can generate more mana the aftermath side can potentially finish some opponents off. Exsanguinate is another slightly less interesting option.
I'd be curious about any feedback or discussion regarding improvements to this list!