Bolas's Citadel + Gray Merchant of Asphodel + Mortuary + Umbral Collar Zealot

B identity

Commander legal

The 4 combo pieces

How to execute it

  1. Cast Gray Merchant either from your hand by paying {3}{B}{B} 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 Umbral Collar Zealot 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 Umbral Collar Zealot ability.
  6. Repeat.

What the combo produces