By taking advantage of it being a first-person story, what if the protagonist could, mistakenly, have self-diagnosed himself (with the help of those he was surrounded by as a kid) as a sociopath, without him actually being one? For him to have been called a narcissist, sociopath, psychopath, etc. due to struggling to understand the feelings of others and seemingly lacking emotions of his own. (But him not actually being any of those.)
Over time, as he got into the teens, he learned to fake these responses, and even exaggerate them: he became a large ham, grandiose, extremely bold, outgoing, confident, even arrogant, showing the typical traits of a supervillain: charm, incredible intelligence, witty banter, a level of snark, a fondness for puns, grandiose demeanor and overcomplicated plans, a fondness for loquaciousness, and the like.
And while he maintains a respectable social life, he's still even now polarizing with a lot hating him (and him knowing they hate him) even though plenty like him, and him remembering the comments from when he was younger and couldn't fake these responses.
Still convinced he's a sociopath, and very aware that all of the traits he displays are perfect for being a villain--and then he gains his superpowers and realizes they are perfectly suited for being a supervillain. And he wants the infamy of it as well as the fortune a supervillain can accrue, and just basically assumes that due to being a sociopath with the hamminess of a villain and power set suited for a villain, along with what his ambitions are, of being recognized and appropriately feared and having the pull, the weight, appropriate for his status, that it's inevitable he is going to be one, so he starts his plans to become one.
And then, panicking at the presence of a known threat that could harm him (he's invulnerable from the outside, but some threats can bypass external armor so to speak and this was one of them), in public before having donned his uniform, he uses his powers, and people assume he is an emerging superhero.
He initially thinks this could be an opportunity to take down the superheroes from the inside, thus setting up the narrative for the story, but there's a rather obvious twist, which becomes quite obvious to those with familiarity with conditions: no, he is not a psychopath or sociopath. He's not even a narcissist. Or any Cluster B personality disorder, or Cluster A, or Cluster C, or Haltlose, or Immature, he's none of those.
He is, however...an incredibly high-functioning autistic individual, who despite being on the autism spectrum, is high-functioning enough to have not gotten diagnosed with it, with people assuming he was just a normal, if a bit "mean", distanced, etc., kid.
And yes this does take inspiration from my own life with what I've been called before. (I've been called a narcissist; I've been called some condition similar to narcissism which may be in the Cluster B or Not Specified sections, don't remember what it was; I've been called a psychopath/sociopath; I am in fact none of those, as it's actually being a high-functioning autistic adhd-laden bipolar disorder-suffering transwoman.)
But that's exactly why I think I can write it and write it well.
The ability to mix fiction tropes, like Good Feels Good and multiple supervillain tropes like Large Ham, with a dose of reality with it being a very real underlying condition that went undiagnosed, is right up my alleyway.
And I kinda think I can do it.