K’rrik, Storm Extortionist (EDH / Commander)

This is a K'rrik, Son of Yawgmoth deck that revolves around the Extort mechanic. The core game path is to ramp and cycle in the early game to try and find a creature with Extort (Basilica Screecher, Crypt Ghast, Pontiff of Blight, Syndicate Enforcer, or Thrull Parasite). With these out, use K'rrik's phyrexian mana and all of our cantrips to majorly drain the table. You'll be slowly losing life too, assuming you only get one extort creature out at a time. With three opponents, you actually net 1 life per phyrexian Extort trigger, so if you're using life to pay for your cantrips, you'll slowly run out of it, hence the heavy lifegain/lifedrain theme in the rest of the deck.

Beyond this core, there are several lifegain/K'rrik combos that can be used to end the game. There's only one truly infinite combo in the deck, but most of them should be able to send the game:

Exquisite Blood + Sanguine Bond

K'rrik, Son of Yawgmoth + Pestilence Demon + Rush of Vitality

K'rrik, Son of Yawgmoth + other cards or a life loss outlet + Profane Transfusion

K'rrik, Son of Yawgmoth + Nim Devourer + Blood Artist

K'rrik, Son of Yawgmoth + Crypt Ripper (you'll probably want to give it lifelink somehow, or this is pretty risky)

Aetherflux Reservoir + Bolas's Citadel ( no top cause that's lame and also $70)