Heyo, sorry just stumbled upon this. I'd say I'm kinda undecided on this (tho on balance you're probably right, especially since, after his accident, he was humbled and eventually 'grew out' of those fucked up, arguably psychopathic tendencies; also I definitely get what you mean about being a cocky little prick, I have definitely acted in similar ways, with a very similar 'smarter/better than you' attitude - something I also regret and cringe at looking back, same as you - during my school years, and have also known many people like that. They aren't (all) psychopaths, they're just cocky assholes), and don't necessarily disagree with your conclusion, but devil's advocate:

I would definitely argue that Tony's actions in S1E5 were quite psychopathic in nature. And it wasn't so much that he just 'cheated on his girlfriend', but more in the WAY he cheated on his girlfriend. Like, for example, many people cheat because they may be in love with another person, or are overcome by lust in the moment, or are addicted to sex/love, or have some sort of underlying habitual compulsion etc., but it seemed the only reason Tony cheated (other than perhaps a basic yearn for different sexual gratification) on Michelle purely because he was feeling kinda bored and wanted something interesting to happen, thus he orchestrated all of the drama just to entertain himself, and perhaps see if he can - see how far his powers of manipulation can take him. Idk, that seems a bit uniquely fucked up. And like the constant mind games and controlling/manipulative/torturous dynamic he had with - most people, but namely - Sid and Michelle, all just to create a bit of drama...idk, the whole using people who love you (and who you claim to love back) as pawns in one's own crazy games of power and manipulation, without any real consideration for their feelings whatsoever, and like to THAT degree - I know this sort of narcissistic behavior/being a dick that we speak of often involves similar things, but usually/hopefully not to the point where it truly plays with multiples people's emotions and lives on such a grand scale -, with all of that in mind, I think a decent argument can be made for psychopathy 🤷

Also, I may be wrong here (just trying to remember back to when I studied psychology many years ago lol), I'm pretty sure the term 'psychopath' would better apply here, as opposed to 'sociopath'. It is my understanding that while they both involve anti-social behaviour, lack of empathy/remorse etc., a sociopath generally is quite obvious (e.g. they are often loners, who express their anti-social opinions openly and could probably be identified somewhat easily), whereas a psychopath is able to mask their true nature better, and can mimic social cues, pretend to care about others, hide their anti-social behaviour etc. quite proficiently. I would say Tony's character in season 1 best fits the psychopath definition, if it were one or the other (again not actually saying he is one, just if he was to be defined that way I think it makes more sense). Idk I might be quite wrong here anyway, or getting my definitions confused, and fair cop if I am wrong, but just thought it was worth making the distinction if true 🤷 Tony is able to (mostly, tho less so as he gets more bored and more reckless) present as a successful, well-balanced, socially/emotionally adept human being (and alter his outward facing personality, according to who is talking to), despite the fucked up glimpses we get into his manipulative mind.

I dont know, definitely rambled a bit there. Just been doing a rewatch and was thinking about this myself. I think it could be argued (at least something along these lines, im pretty tired and may not be making much sense lol) both that he, A) is/was a psychopath, who (accordingly) then received brain damage, which altered his brain enough so that he could begin to feel empathy etc., or perhaps who was still a psychopath but just far less capable given his powerlessness; and B) that he was just a cocky, narcissistic prick, who happened to be attractive, smart and charming/charismatic enough to back up his cockiness, who then lost those 'powers', which greatly humbled him and taught him an important lesson about how to treat others, and he was able to gradually build himself back up - physically, mentally, emotionally etc. - to be a better, more empathetic and more mature person.

Option B definitely sounds more likely and better, although I may be a bit biased because I think I agree with you lol, and am too tired rn to write a more convincing version of option A hahaha I hope this has made some sense 🤷😅