Goblin Welder + Thornbite Staff

Goblin Welder
Thornbite Staff

Requires
All permanents on the battlefield. Thornbite Staff attached to Goblin Welder. Goblin Welder does not have summoning sickness. You control at least one nontoken artifact creature. You have at least one artifact creature in your graveyard.
Steps
  1. Activate Goblin Welder by tapping it, sacrificing any artifact creature you control and returning any other artifact creature from your graveyard to the battlefield
  2. Goblin Welder triggers, untapping itself
  3. Repeat
Results
Infinite ETB. Infinite LTB. Infinite death triggers. Infinite sacrifice triggers.