Rionya, Fire Dancer + Combat Celebrant

Rionya, Fire Dancer
Combat Celebrant

Requires
All permanents on the battlefield.
Steps
  1. At the beginning of your combat phase, Rionya triggers, creating at least one token copy of Combat Celebrant with haste
  2. Declare the Combat Celebrant token as an attacker, choosing to exert it as it attacks
  3. The Combat Celebrant token triggers, untapping all other creatures you control and causing you to get an additional combat phase after this one
  4. Repeat each combat phase
Results
Infinite combat phases. Infinite creature tokens with haste. Infinite ETB. Infinite LTB.