my evil AU is just a revenge fantasy I think. (blows a bubble) talking more of evil!ken -> evil!kaz, here. evil!kaz interests me too and i have thoughts on his backstory/motivations/etc, but. later!
... i've written about their first meeting (sensitive, UST) summary: ken jumps him at a job, imagine a car shop’s hangar, vehicles suspended in midair, buckets in corners, and like a surgeon's tray of repair tools. strong gasoline smell naturally overpowers the blood and some blood splatter was there Already. [...] ken emerges from his hiding place to discuss a long-term partnership. no not like that. yet. patience…
during this ken reveals he knows of kaz's hemophilia, which is Doctor-Patient Confidentiality, so - ken reveals that he has the upper hand, but nothing else, and kaz doesn't ask exactly how much ken does know. ken wants his services (cleanup/coverup) and will pay handsomely yada yada.
the two don't get attached until kaz has a fainting spell at a job. instead of irritation, or fear for discovery, etc ken is! empathetically! worried for kaz. this is 1. new 2. scary 3. Exciting. his interest in kaz pivots from smth professional/at-a-distance to something romantic, and consequently, darker.
who are you, kamimura? of course, before meeting him at that car shop - ken had skimmed thru his files - irrelevant, unimportant, hm-? harassed? bullied? kids sure can be cruel. (tucks this away mentally. a weakness of kaz's. something to hold over his head, i-if it's necessary! which it won't be...!) now, he's invested. kaz has made something crystal clear though: don't dig anymore. value my privacy.
let's be real. it's not as though kaz would KNOW. if ken reopened his documents. totally unaware unless ken slips or outright tells him. but - ken listens to kaz, in all universes, and he does have morals, that he adheres to quite strongly! it is his morals that propel him to do "evil" in this scenario (and in canon). wishes he had read carefully the first time, is all. ~~;; ... bad at boundaries but he understands 'don't know more than i tell you'.
...so, for awhile, ken doesn't know exactly what that bullying entailed. why kaz dropped out. he doesn't know that kaz stopped eating, leaving bed, using the bathroom, bathing/showering, because Something Bad happened at school.
when, ken, eventually does. learn, and know. well this is why "i burn" is on that playlist!!!!!!!
rough designs for the unaware also, art by me on top [obv] and best friend for the last 3 [also obv]