Port Razer + Helm of the Host

Port Razer
Helm of the Host

Requires
All permanents on the battlefield. Helm of the Host attached to Port Razer. An opponent is unable to block Port Razer.
Steps
  1. At the beginning of combat, Helm of the Host triggers, creating a token copy of Port Razer with haste
  2. Declare the Port Razer token as an attacker
  3. When the Port Razer token deals combat damage, it triggers, causing you to untap all creatures you control and get another combat phase after this one
  4. Repeat
Results
Infinite damage. Infinite creature tokens with haste. Infinite combat phases. Infinite combat damage. Infinite ETB. Infinite untap of creatures you control.