Teysa Karlov + Pitiless Plunderer + Bloodsoaked Champion + Altar of Dementia

Teysa Karlov
Pitiless Plunderer
Bloodsoaked Champion
Altar of Dementia

Requires
All permanents on the battlefield. You have attacked with at least one creature this turn.
Steps
  1. Activate Altar of Dementia by sacrificing Bloodsoaked Champion
  2. Pitiless Plunderer triggers twice, creating two Treasure tokens
  3. Resolve the Altar of Dementia ability, causing target player to mill two cards
  4. Activate the Treasure tokens by tapping and sacrificing them, adding 1b
  5. Activate Bloodsoaked Champion by paying 1b, returning it from your graveyard to the battlefield tapped
  6. Repeat
Results
Infinite ETB. Infinite LTB. Infinite death triggers. Infinite sacrifice triggers. Infinite mill. Infinite self-mill.