Impostor Syndrome, and Breath of Fury

Prerequisites

• Impostor Syndrome on the battlefield
• Breath of Fury on the battlefield

Steps

1. Deal combat damage to an opponent using the nontoken creature that has haste and the creature that has Breath of Fury attached
2. Breath of Fury and Impostor Syndrome trigger
3. Resolve the Impostor Syndrome trigger, creating a token copy of the nontoken creature with haste that isn't legendary
4. Resolve the Breath of Fury trigger, sacrificing the creature it is attached to and attaching it to the creature token created in step 3, then untapping all creatures you control and causing you to get an additional combat phase after this one
5. Repeat each combat phase

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite combat phases
• Infinite untap of creatures you control
• Infinite mana creatures you control can produce
• Infinite combat damage