ToME: the Tales of Maj'Eyal

I had something like 85 Accuracy stat before fighting a unique Farplane boss, an Oozing Horror. During the fight it lowered my accuracy with something, and that was apparently permanent.

I now have 0 Accuracy stat despite quite a number of modifiers for it and the character is basically utterly useless.

Did you by any chances have the cursed aura tree ?

I do not.