If i become immune to fatigue can i uses bolstered résilience on every attack
Bolstered Resilience
You can dramatically increase your damage reduction in exchange for its temporary loss.
Prerequisite: Damage reduction.
Benefit: As an immediate action, you can double your DR against a single attack, to a maximum of DR 20. The type of the DR remains unchanged. If the attack you are guarding against is not successful, the increased damage reduction persists until you are hit with an attack or until the start of your next turn, whichever happens first. At the start of your next turn, you become fatigued. You cannot use this feat while you are fatigued.
It wouldn't let you use it on every attack.
Just every round since being immune to fatigue doesn't allow you to have more Immediate Actions or change this part;
"the increased damage reduction persists until you are hit with an attack or until the start of your next turn, whichever happens first."
You could use it every round, but not against every attack. It would still only be good against 1 attack per round.
It requires an immediate action, and you only get 1 of those per round.
Ok so just against frist hit each round still pretty nice.