Demonlord Belzenlok will flip through our deck to find one of our 3 cards with CMC 3 or less to let us win the game...or we'll just kill ourselves with the damage first. Running 40 non-land cards is about the max I think we can have without further risking knocking ourselves out of the game after one or two castings of Belzenlok. Having 3 cards to stop us feels fine, but Zombie Infestation is on the chopping block if we decide to risk going to just 2 cards.
The first plan of action is to get Whip of Erebos into play before we play Belzenlok. Doing this will negate any of the damage done by Belzenlok's ETB trigger. Casting Belzenlok without the whip is possible, but you risk taking lethal damage.
Ramp:
We are running 60 lands so the majority of the time we will continue to hit our land drops through turn 6. Ramping into more manna can help us play Belzenlok and another threat in one turn, but we are limited to manna rocks with CMC 4 or greater so that we can consistently hit one of our target cards. Our total ramp package includes Crypt Ghast, Cabal Stronghold, Crypt of Agadeem, Magus of the Coffers, Paradise Plume, Hedron Archive, Ur-Golem's Eye, Contract Killing, Corpsehatch, Dread Drone, and Skirge Familiar.
Win conditions:
Our first win-con is Faith of the Devoted. Ideally, you can get Skirge Familiar onto the battlefield and have a large hand of cards. Discard 15 cards to the Skirge to get 15 manna to then use to pay for the 15 discard triggers of Faith of the Devoted. This is my preferred method of winning as this hits each opponent for 30 life while also gaining us 30 life. If we find ourselves with plenty of manna and cards in hand at the end of the turn we can use that manna during our clean up step to drain our opponents as we discard down to 7 cards. Zombie Infestation can be used to trigger the discard too with the benefit of giving us a handful of zombies.
The second big hitter is Dying Wish. By throwing this enchantment onto Horror of the Broken Lands during the first win-con and sacrificing it to Fallen Angel or Dimir House Guard we can drain one opponent for an additional 30+ life. Other large targets for Dying Wish are Bonehoard, Mortivore, or Lashwrithe. Ob Nixilis, Unshackled or Fallen Angel can work as well provided we find enough creatures to die first.
The final card in our deck with CMC less than 4 is Zombie Infestation. With enough cards in hand, we can make a small army of zombie tokens. Attacking with this army should take a decent chunk out of our opponents' life totals. To strike the final blow, we can cycle Gempalm Polluter, sacrifice our army to Fallen Angel, and cast Flesh Allergy.
Getting our final cards:
We have a few ways of digging out the cards we're looking for to close out the game. Treasure Keeper can dig out one of our 3 cheap cards and cast it all for the cheap price of dying. We also run a slew of tutors to dig up the important pieces: Beseech the Queen, Diabolic Tutor, and Final Parting. Brainspoil can be transmuted to find Skirge Familiar, Horror of the Broken Lands, or Fallen Angel while Dimir House Guard will often be transmuted to find Whip of Erebos.
If you find that you need another ETB trigger off of Demonlord Belzenlok you can find a few different ways to sacrifice him and recast. My personal favorite way to get another trigger is to use Rescue from the Underworld, sacrificing Belzenlok, and getting one of our other creatures back onto the battlefield. Doing this on your opponent's end step almost guarantees the game will end during your turn (either for you or them).
Staying Alive:
We've put a few board wipes, targeted removal, and life gain cards in the deck to keep our opponents creatures off our life total. After all, that's our precious life total and we plan to hurt ourselves a good amount before the game is over.
So you've accidentally drawn your whole library and need one more turn to kill your opponents. How do we stay alive and keep from milling ourselves out? Junktroller can recover any card we need from our graveyard back to our library for us to draw again. Dread will get put back into our library any time it would wind up in the graveyard. Discarding it during the clean up step will work if we can't actively discard it with Skirge Familiar or Zombie Infestation. If it's out on the battlefield, you'll need to use Dimir House Guard or Fallen Angel to sacrifice it before your draw step. Inverter of Truth is your last shot at staying in the game and offers you a second chance of hitting your key cards from the graveyard.
