Aurelia, the Warleader + Helm of the Host

Aurelia, the Warleader
Helm of the Host

Requires
All permanents on the battlefield. Helm attached to Aurelia.
Steps
  1. At the beginning of your combat phase, Helm of the Host triggers, creating a nonlegendary token copy of Aurelia
  2. Declare the token Aurelia as an attacker
  3. The token Aurelia triggers, causing you to untap all creatures you control and 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 untap of creatures you control.