User blog comment:Kyran Kandosa2/An PSA on Berserks and other "Rage Mode" Semblances, Part 1: The basics/@comment-17970636-20140715045955/@comment-24901923-20140715130708

Yang seems more or less an "Rage Mode" character than a proper Berserk in any way. Given her association with fire, a temperment to match is unsurprising. Whether or not this is obsolete in Canon is probably irrelevant for Fanon purposes, as the general Fanon rule seems to be that pretty much anything goes that doesn't directly contradict known Canon in some fashion.