Breath of Fury attached to another artifact creature you control.
An opponent cannot block creatures you control.
Steps
Deal combat damage to an opponent using the creature with Breath of Fury attached, triggering Breath of Fury and Sharding Sphinx.
Resolve the Sharding Sphinx trigger, creating a 1/1 Thopter artifact creature token.
Resolve the Breath of Fury trigger, causing you to sacrifice the creature it is attached to, then attach Breath of Fury to the Thopter token, then causing you to untap all creatures you control and to get an additional combat phase after this one.