The whole “fictionkin” thing is not something that I do, and I don’t really even understand how it works – I have no issue with people who do that, though; to each their own – but it would be reasonable to say that there are some fictional characters with whom my personality and beliefs are eerily in sync.
Chief among them is Darth Plagueis (specifically, as portrayed in the Star Wars novel Darth Plagueis by James Luceno). Not only do I connect very strongly to his personality, ideals, goals, and way of thinking, but it would also not be a stretch to say that his portrayal in that book is as an antisocial narcissist, just like me. I’m fairly certain that he was not intended to be a relatable character to most people, but then, I’m not most people.
The runner up is Ozymandias from the film Watchmen, whose worldview lines up so well with my own that I did not realize he was supposed to be the villain of the story until that misunderstanding was pointed out to me.
Honorable mentions - a strong match to parts of my personality, but too many differences to be considered similar to my personality in general - include, in no particular order: Anakin Skywalker / Darth Vader (Star Wars), Zuko and Azula (Avatar: The Last Airbender), Louise Belcher (Bob’s Burgers), and perhaps surprisingly, Lisa Simpson (The Simpsons).