Breath of Fury and Determined Iteration on the battlefield.
Breath of Fury attached to another creature you control that can attack this turn.
You control at least one creature token.
An opponent cannot block creatures you control.
Steps
At the beginning of your combat phase, Determined Iteration triggers, creating a token copy of a creature token you control with haste.
Deal combat damage to an opponent using the creature with Breath of Fury attached.
Breath of Fury triggers, causing you to sacrifice the creature with Breath of Fury attached, then attach Breath of Fury to a creature token you control, untap all creatures you control and to get an additional combat phase after this one.