So context (you might wanna know Yosemites story for this to make sense): This girl was the biggest fan of Yosemite back when they pretended to be a hero so when they started causing havoc just for the fun of it they didn't question anything and just trying to see what havoc she could cause. Her havoc started getting bigger and Yosemite noticed this and offer to let her join them. Of course she said yes because this was her idol and now she helps fight Cosmellas Knights and cause havoc with Yosemite who's now kind of her parent
Fun fact, this henchmen was inspired by Candy Apple Cookie because Yosemite was kinda inspired by Shadow Milk Cookie (however unlike Candy Apple she isn't simping for Yosemite and Yosemite actually gives a shit about her)
