Black Mist Move Introduction
The description of Black Mist in the encyclopedia is that it corrects and eliminates the ability changes (including hit rate and dodge rate) of all Pokémon on the field. Using this move will not be considered as reducing ability by Eternal Purity, White Smoke, Metal Protection, Flower Curtain, Super Strength Claw, Strong Chest Muscles, and Sharp Eyes.
The description of Concentrated Energy is that it puts the Pokémon into a vulnerable state. The hit rate of Pokémon in the vulnerable state increases by 2 levels.
There is no vulnerable state that can be cleared by Black Mist
However, in the description of vulnerable state, it is said that the first generation can remove vulnerable state. This page of the encyclopedia has not been updated for a long time, and it is now the ninth generation.
Then the encyclopedia description of Black Mist shall prevail. The objects that can be cleared and strengthened do not include vulnerable state, so the Concentrated Energy state cannot be cleared.
Do you understand what I mean!