Breath of Fury attached to any other creature you control with an egg counter on it.
You control at least one additional creature.
An opponent cannot block and kill creatures you control.
Steps
Declare Xira and the creature with Breath of Fury attached as attackers.
Xira triggers, putting an egg counter on any other creature you control.
Deal combat damage to an opponent using the creature with Breath of Fury attached and Xira.
Breath of Fury triggers, causing you to sacrifice the creature it is attached to, then attach Breath of Fury to any other creature you control with an egg counter on it, then causing you to untap all creatures you control and to get an additional combat phase after this one.
When the creature that had Breath of Fury attached dies, Xira triggers, causing you to draw a card and create a 1/1 Insect creature token.