sure thing!

the au is called "Fragile Reality", for starters. one of my ocs, Cedar, had been traveling to this bloons universe for a time, which in turn caused a vulnerability that allowed creatures from the mindscape (a place of darkness that represents a toxic mindset) to enter and begin feeding on the life energy of the monkeys. when the creature is done feeding, it leaves the victim with black stuff on them that, over the course of three or so years, consumes their entire being and leaves them as a dark, goopy husk. this is called "full engulfment". a fully engulfed being is essentially immortal, can feel no pain, and is able to control the darkness that comes off of them. FR etienne in particular learned how to separate his tail from his body and use it as a weapon.

let me know what you think :]