Vim isn't affected by fatigue.

[yufra]

mod.class.Actor:preUsetalent doesn't calculate fatigue into the vim cost, and psi uses self.fatigue instead of self:combatFatigue (possibly intentional, just pointing it out).

[Sradac]

Someone pointed out elsewhere fatigue ONLY affects stamina and mana costs and is intentional.

[yufra]

I know, I replied to that thread. Fatigue affects much more if you look at the code.