Mortuary + Gray Merchant of Asphodel + Woe Strider + Bolas's Citadel

Mortuary

Gray Merchant of Asphodel

Woe Strider

Bolas's Citadel

How it works

1. Cast Gray Merchant either from your hand by paying 3 or from the top of your library by paying 5 life.
2. When Gray Merchant enters, it triggers, causing each opponent to lose life equal to your devotion to black and causing you to gain life equal to the life lost this way.
3. Activate Woe Strider by sacrificing Gray Merchant.
4. When Gray Merchant dies, Mortuary triggers, putting Gray Merchant from your graveyard onto the top of your library.
5. Resolve the Woe Strider ability.
6. Repeat.

This brilliant loop transforms your library into an endless engine of drain and recursion. By allowing you to cast Gray Merchant of Asphodel directly from the top of your library using Bolas's Citadel's life-payment ability instead of its mana cost, you can repeatedly trigger its devotion drain. Each time it enters, you simply sacrifice it to Woe Strider, whose presence also provides the initial Goat token and a convenient way to sculpt your draws. Whenever the Merchant hits the graveyard, Mortuary instantly redirects it right back to the top of your library, ready to be recast by the Citadel while the lifegain from the Merchant safely offsets the life you pay to cast it.