Renegade Rallier + Saffi Eriksdotter + Altar of Dementia

Renegade Rallier
Saffi Eriksdotter
Altar of Dementia

Requires
Access to the graveyard, creature and artifact abilities. All permanents on the battlefield.
Steps
  1. Have Renegade Rallier, Saffi, and Altar of Dementia on the battlefield
  2. Use Saffi's ability, sacrificing itself, targeting Renegade Rallier
  3. Sacrifice Renegade Rallier to Altar of Dementia, milling an opponent for 3
  4. Renegade Rallier returns to the battlefield from Saffi's delayed trigger
  5. Using Renegade Rallier's ETB ability, target Saffi and return Saffi to play
  6. Repeat steps 2-5 until you mill your opponent completely
Results
Infinite mill. Infinite ETB. Infinite LTB. Infinite sacrifice triggers. Infinite death triggers.