Infinite creature LTBInfinite creature ETBInfinite creature sacrifice triggersInfinite death triggersInfinite combat phasesInfinite untap of creatures you controlInfinite mana creatures you control can produceInfinite combat damage
How it works
Deal combat damage to an opponent using the nontoken creature that has haste and the creature that has Breath of Fury attached.
Breath of Fury and Impostor Syndrome trigger.
Resolve the Impostor Syndrome trigger, creating a token copy of the nontoken creature with haste that isn't legendary.
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.