I think Rick and Morty is a perfect example of this done correctly the mentor needs to have personal struggles to remain dynamic. I really enjoyed this topic.
I think that it could evolve into something more than a one off though there are many scenarios like: First time mentoring students First betrayal by a student Temptations Learning to let students be themselves and craft their own style or adjust A mentor who tries to replace his old students with new ones because of past failures A mentor balancing his own dedication to the students maybe they are too invested and don't give enough time to family or friends because of their love for the craft. All of these could be implemented across a series of stories
I just looked at a book in the library yesterday that had this exact character in it, I think it was called The Deamon Prism.... Can't quite remember. It was about a mage who lost his sight, and the only thing that keeps him going is training an apprentice. They then enter another world where it turns against you and is like a hallucination... Anyways, loved the idea of it and nearly got it, so please write something with a mentor! It's a neat idea
Sorry to necro bump it again, but the current book I'm writing might possibly be done best this way. I'm still deciding. But there are MANY examples of a mentor main character. However it really does depend on what you mean by "mentor". Think about every kids team sport movie you've ever seen. <Bad quality> person coaches plucky losers and along the way learns how to fix his own flaws. Techincally in these situations the mentor is actually the kids but like I said it depends on what you mean. The Mentor (movie term) is the kids but the mentor (laymans term) is the coach. Mighty Ducks is a great example. If you want the "Mentor" to also be the main character then you need to have that person inspire themselves. Which doesn't really gel well with most people because while we may have drive, we tend to look for inspiration outside of ourselves.
"Gran Torino" is the only title that springs to mind right now but there are tons of similar stories about a good citizen who picks an unruly teenager and changes them around *yawn*