Indeed. And from wiki informations this burst gauge gain decrease is ridicously high (1 burst gauge per attack), but it's considered debuff. Passive makes her hit all enemies.
I see...
Then comes probably the question that might make her broken in certain contents(?):
Say I have 3 enemies on the field and I get her to do a normal attack without the debuff. Will she gain 10 burst, or 30 burst from hitting all 3 enemies?