For what it's worth, I think Hakke-Cannon is a good way of translating it.
Yeesh...it's 'cause my magic's practically zip that y' gotta watch y' don't mess with me too much, Purple Girl!!Gear up!VWSHKHakke-Cannon: Rapid-Fire Mode, three rounds! Not sure if I should translate "hakke" (eight trigrams), considering the fandom generally knows her "eight-trigram reactor" as the "Hakkero".FROOSHVWASSH発射!!