How can you create a combo with Mairsil, the Pretender, Endling, Cauldron of Souls, Blood Vassal, Urabrask the Hidden?
user
[START OF COMBO]This combo can be formed with Mairsil, the Pretender, Endling, Cauldron of Souls, Blood Vassal, Urabrask the Hidden

Color identity: UBR
Mana cost: 
Steps:
  1. Activate Mairsil using Cauldron of Souls' ability by tapping it, giving itself persist until end of turn.
  2. Activate Mairsil using Blood Vassal's ability by sacrificing it, adding {B}{B}.
  3. When Mairsil dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
  4. Activate Mairsil using Endling's third ability by paying {B}, giving Mairsil undying until end of turn.
  5. Activate Mairsil using Blood Vassal's ability by sacrificing it, adding {B}{B}.
  6. When Mairsil dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
  7. Repeat.[END OF COMBO STEPS]

Result:
  - Infinite black mana
  - Infinite death triggers
  - Infinite enters the battlefield
  - Infinite leaves the battlefield
  - Infinite sacrifice triggers[END OF COMBO RESULT][END OF COMBO]

Other prerequisites:
  - Mairsil, the Pretender must be on the battlefield
  - Endling must be exiled
  - Cauldron of Souls must be exiled
  - Blood Vassal must be exiled
  - Urabrask the Hidden must be on the battlefield
[END OF COMBO PREREQUISITES]
assistant