Feldon of the Third Path + Diamond Lion + Thornbite Staff + Altar of the Brood

Feldon of the Third Path
Diamond Lion
Thornbite Staff
Altar of the Brood

Requires
Diamond Lion in graveyard. All other permanents on the battlefield. Feldon of the Third Path does not have summoning sickness. Thornbite Staff attached to Feldon of the Third Path. 2r available.
Steps
  1. Activate Feldon of the Third Path by paying 2r and tapping it, creating a token copy of Diamond Lion with haste
  2. Altar of the Brood triggers, milling each of your opponent for one
  3. Activate Diamond Lion by tapping it, discarding your hand, and sacrificing it, adding rrr
  4. Thornbite Staff triggers, untapping Feldon of the Third Path
  5. Repeat
Results
Infinite mill. Infinite ETB. Infinite LTB. Infinite death triggers. Infinite sacrifice triggers.