What about an AU where Izuku is The Consulting Villain, someone who gets hired to plan out jobs using the information available to figure out which hero they'd be dealing with? His only stipulation beyond his hourly pay for a consultation is no killings.
Series: Boku no Hero Academia AU Criteria: If you have a job and need help making a plan, you can hire him, but you better follow his rules. You will not make that mistake twice. AU title (optional): Green Gremlin
Izuku had dreamed of being a hero, dreamed of showing the world how to save people with a smile… and then the prejudices of people, even his idol All Might, crushed his hopes and dreams. So he decides that he will change the heroes by making them be better.
After his years of stalking hero forums, he has found more than a few hidden villain forums. Snooping around, he finds a minor villain that seemed malleable enough to sway to his thoughts. He arranges a blind meet with the forum user Camilla, who turns out to be Himiko Toga just on the cusp of breaking into a blood frenzy once more.
He feeds her, and helps her recover, teaching her to only take what she needs instead of killing people. She becomes his loyal minion and bodyguard. She also begins striking out guided by his plans, and gets away with everything shy of murder.
This success leads to more job requests coming in. Many are just for advice on the heroes that might come in, some are how to escape (some villains see the value in not escalating to killing the heroes), and more than a few to improve their performance. He has only one rule for them, aside from half upfront half afterwards, no killing.
One villain think they are above that rule, actually more attempted to skimp on the payment, the villains that are that stupid, they do not make the mistake a second time. In fact, they tend to vanish quietly, appearing months later at police stations, looking horrified, broken, and begging for a safe cell to keep Him away. For He would not dare come to the police station for them.
When heroes and police ask, they will only tell them of the Green Devil himself. The smile in the shadows. The puppetmaster of hell Himself. He only goes by Green Gremlin.
