Just me thinking today but...
You can actually become Fatigued while Fatigued! (and possibly even Fatigued while Exhausted, although that ones much much trickier...)
Fatigued:So if I am Fatigued, and would again become Fatigued, I become Exhausted instead...normally.Doing anything that would normally cause fatigue causes the fatigued character to become exhausted.
BUT! What if we use Furious Finish/Roused Anger combo!
Roused Anger lets us Rage while Fatigued, and afterwards we become Exhausted. Now, normally, Exhausted would override the normal Barbarian Fatigue, but Furious Finish says:So after a Roused Anger Rage, you become Exhausted AND Fatigued, because the Furious Finish feat works BOTH ways!If you do, your rage immediately ends, and you are fatigued (even if you would not normally be).