So I am working on a new fantasy novel and I need to introduce a mentor character someone to guide the hero and get the adventure of its way. The problem is I don't know how I want to do it. One of my ideas was to do a goofy and dumb wizard that really doesn't know what they're doing the problem with this though is that I don't want the story to lose its darkness or seriousness that I've kept thus far my other idea was to do a cookie cutter badass mentor character though that might seem a bit cliché and make my story seem a little bit like a carbon copy of every other fantasy novel
I'd try making a list of what the mentor needs to teach / wants to teach. Then brainstorm a list of people who can teach that. Look deep into the list.
On top of what John already suggested, ask yourself this question: Who do you want this mentor to be to your MC? Do you want the mentor to be a mother/father figure, leading them into the future to replace them? Do you want them to be more of a peer that pushes our hero to greater heights through competition? Hell, you could even have the mentor be more of an adversary that the MC has to overcome in order to meet their goal, so they learn through conflict.
I think your first instinct is good. Remember how Yoda first appeared to Skywalker? Ask yourself what you want the protagonist to learn, then decide on a bumbling way to show this. The mentor could be a real fool that ends up on his feet like a cat or just pretending to be one. There was a movie called "Being There," Peter Sellers plays an excellent simpleton who solves everyone's problems because of how they interpret his words. A bumbling fool can be fun because it will bring out frustration from the reader when he leads the protagonist into danger, a great set up if you ask me. It can also be fun with humor. Jackie Chan does this the best. His movie Drunken Master is a classic. Have fun and good luck.
I think it all depends on what kind of mentor they are: - A been there done it mentor by experience kind of person - just there to be a comfort and a support, almost like a cheerleader? - active in the persons mentorship? - What kind of power do they have over the mentee? - Are they an unwilling mentor? like Haymitch in hunger games - Are they a kind of conscience i.e. jimney cricket in Pinocchio. There are plenty of things you can do to prevent your mentor turning into a cliché But also if you want some more helpful answers I suggest giving a tad more detail!
Just my personal opinion, but perhaps a once powerful wizard who made a foolish mistake long ago and is no longer interested in apprenticing. It could be that the MC's journey is what the Mentor needs, as well, to forgive himself and let go of the past. It's a bit formulaic but, in my opinion, it works better for a dark story to make the Mentor an interesting character rather than a comedic or perfect one.
Every character (wether author likes it or not) is derived from a previous character. Don't be ashamed of having your character being too similar to another. However, in order to avoid direct "carbon copies", I have something I have for all my characters what I call an influence dice. This is a list of characters combine make up my character. The latest example I have is of my charcter, Carmin, who is from a magical girl esque fantasy that takes place in modern day America. My characters of influences are Ariel from the Little Mermaid, Usagi/Serena from Sailor Moon (the live action incarnation), Willow from Buffy and the Yoruba goddess, Yemoja. I've taken qualities of these charcters and fused them together to make my own characters.
