Feldon of the Third Path + Diamond Lion + Thornbite Staff + Stalking Vengeance

Feldon of the Third Path
Diamond Lion
Thornbite Staff
Stalking Vengeance

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. Activate Diamond Lion by tapping it, discarding your hand, and sacrificing it, adding rrr
  3. Thornbite Staff and Stalking Vengeance both trigger
  4. Resolve the Stalking Vengeance trigger, dealing damage equal to Diamond Lion's power to any target
  5. Resolve the Thornbite Staff trigger, untapping Feldon of the Third Path
  6. Repeat
Results
Infinite damage. Infinite ETB. Infinite LTB. Infinite death triggers. Infinite sacrifice triggers.