Finn is another of the more recent additions to the Star Wars universe. Like Rey and Poe, he was introduced in Star Wars: The Force Awakens. The new trio of characters mirrors Luke, Han and Leia quite a bit, but there are still some significant differences. We learned more about Han in Solo: A Stars Wars story, and while he “enlisted” with the Empire, he wasn’t as deep into things as Finn was. Finn was so engrained in the First Order that he didn’t even have an actual name.
We’ve seen people defect before, but with Finn, it felt more traumatic. He had blood smeared across his stormtrooper helmet and froze up. He was never cut out for the First Order, and as soon as he realized that, he got out, with a little help from Poe.
Between The Force Awakens and The Last Jedi, we see Finn grow quite a bit as a character. In the first of the new movies, he didn’t really know what to do. He was being protective of Rey, who didn’t much need his help (which he learned eventually). In The Last Jedi, he’s ready to sacrifice himself to save the others before Rose keeps him alive.
There has yet to be a time when Finn’s actions didn’t seem sincere. He wants to help people and he’s just figuring out the best way to do it. The same followed in The Rise of Skywalker, where even when the going got rough, he toughed it out with the Resistance and saw them through to victory. He’s an admirable character.