I watched what I am almost certain was a two or three part movie miniseries (like two movie length episodes to the same story) when I was young, so I’m guessing it was probably from the late 90s up to 2010 at the latest. It was set in a fantasy medieval world, where the male main character went to some sort of magic school/library and learnt a lot of powerful things, including I think learning the true names of some magical beings which gave him power over them. It was bad magic or something though, and he ended up either making a pact with or being hunted by an evil black shadow that showed itself as an alterego. There was a scene where he was being hunted by it on a boat trying to escape a city, and I believe the last movie ends with him going through a massive ornate door, and he is finally forced to face the evil monster that has been hunting him his whole life on the other side. It’s killing me not remembering, so any help would be so greatly appreciated!
Earthsea (2004).