How can you create a combo with Deathrender, Gravedigger, Eternal Witness, Altar of Dementia?
user
[START OF COMBO]This combo can be formed with Deathrender, Gravedigger, Eternal Witness, Altar of Dementia

Color identity: BG
Mana cost: 
Steps:
  1. Activate Altar of Dementia by sacrificing Eternal Witness.
  2. Eternal Witness dies, triggering Deathrender, putting Gravedigger from your hand onto the battlefield and attaching Deathrender to it.
  3. Gravedigger enters the battlefield, returning Eternal Witness from your graveyard to your hand.
  4. Resolve the Altar of Dementia ability from step 1, causing target player to mill cards equal to Eternal Witness' power.
  5. Activate Altar of Dementia by sacrificing Gravedigger.
  6. Gravedigger dies, triggering Deathrender, putting Eternal Witness from your hand onto the battlefield and attaching Deathrender to it.
  7. Eternal Witness enters the battlefield, returning Gravedigger from your graveyard to your hand.
  8. Resolve the Altar of Dementia ability from step 5, causing target player to mill cards equal to Gravedigger's power.
  9. Repeat.[END OF COMBO STEPS]

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

Other prerequisites:
  - Deathrender must be on the battlefield
  - Gravedigger must be in your hand
  - Eternal Witness must be on the battlefield
  - Altar of Dementia must be on the battlefield
  - Deathrender attached to Eternal Witness.
[END OF COMBO PREREQUISITES]
assistant