Breath of Fury attached to a creature you control that can attack this turn.
An opponent cannot block creatures you control.
Steps
Declare the creature with Breath of Fury attached and Otharri as attackers.
Otharri triggers, causing you to get an experience counter and create a number of 2/2 Rebel creature tokens equal to the number of experience counters you have that are tapped and attacking.
Deal combat damage to an opponent using the creature with Breath of Fury attached and Otharri, causing you to gain life equal to the amount of damage Otharri dealt.
Breath of Fury triggers, causing you to sacrifice the creature with Breath of Fury attached, then attach Breath of Fury to a Rebel token, untap all creatures you control and get an additional combat phase after this one.