My main character trained his whole life to be an exorcist, but ended up failing the maximum amount of times required to become one when the time came. Years passed and he decided to give up and live a normal life. Right before he leaves his hometown he gets attacked by demons and awakens to a unique power that is explained how later in story. Anyways someone finds him and explains how he isn't the only one with these powers and should join him. What I'm trying to figure out is why would he join the group? My character has no vendetta for any bad guy, no wish that needs granted, or anything like that. He was pretty much about to go to college on a scholarship and start the rest of his life. Why would he throw that away to go back to a life that has shut the door on him? One more thing it has to be of his own free will.
Why did he want to be an exorcist in the first place? He trained all his life and took the test multiple times, so that implies that he has some kind of reason for doing so - something beyond "because it would be fun".
Put simply, danger. If I was you I'd probably make it so he's being watched constantly by demons and it starts getting worse to where he has to put up crosses and/or salt, etc to keep them away and ends up deciding that maybe the group wouldn't be such a bad thing.
Wants to live a purposeful life? Saw things when he was training that made him realize how important the job is? A lot of this is going to depend on characterization, and you're the one who knows this character. What personality traits or experiences has he had that makes this decision make sense?
Have the demons come for someone he loves? Or . . . in the name of what Entity or Power is he supposed to be exorcising those demons? (You don't go up against them in your own human strength. That'd be like facing a nuke with a popgun.) Has he received what he takes to be a direct command from that Entity or Power that he must get back in there and try again because this time he'll be given the key to tapping into that Power? If the idea of your story is that certain humans do have anti-demonic powers in themselves {" . . . he isn't the only one with these powers . . . "), then you've got some problems to solve. Because a) if he's flunked the test so many times, he doesn't have what it takes and why would this group seek him out? And b) he would already know there were other people who had the powers he lacks, as this culture has an exorcist training program with, presumably, other students taking and passing it. So you'll have to decide what attraction some stranger going, "Psst! Hey, buddy!" in a back alley (so to speak) would offer. That may seem to be the same as your original question, but you're the best one to answer it, out of the world you've envisioned. Does this mysterious group offer him sure-fire success at the exorcism business this time around? If doing this exorcism thing was a lifelong dream, that might be incentive enough to make him join with them and try again. Your challenge would be giving a good reason for him to believe them--- even if it turns out to be some kind of scam.
-Because he's enthralled with the occult (demons, exorcism, ghosts, etc) and the normal life is too mundane for him. -Because his life might be in danger if he doesn't learn to control his new found power. -Because the person recruiting him is someone he had studied in his exorcist days. -Because he's a loner and an outcast due to his previous vocation, and this gives him a chance to connect with people like him. -Because he feels his new found ability is something that can help people, which might be why he wanted to be an exorcist in the first place. -Because someone he loves is in extreme danger; and if he wants to save that person, he has to join the others and learn how to use his power.
What about good old human curiosity? If these powers are not considered normal, maybe he wants to find out what they're about.
as I wrote in my wip "because the enemy of my enemy is a dodgy bastard I don't entirely trust either"
Your protagonist could shine brightly as a target for demons, as their potential only threat, those with the power to exorcise them would become HVTs...? Gives good enough reason to me for him to join forces with another like minded individual because strength in numbers
I think if I was rejected from a way of life that I worked hard to earn, then I would have a need to prove myself. As much as I would want to turn away and start the rest of my life, I wouldn't be able to leave it alone. A masochistic tendency towards self-sabotage? Or someone tells him he can't do it. Competitiveness can take a character far down a rocky road with no other reasons.
Even though someone is a stranger, you can connect with them on a strong level. As a newly awakened Exorcist, would it not be reasonable to be sensitive if not overwhelmed by the auras surrounding you? Then let us take that question as a jumping point and ask, would you attach yourself to the one calming factor in a chaotic setting? Tack on that this was something that he wanted to be so badly, if you got the chance to do the one thing you always regretted never doing/being able to do, would you do it?
I think I might make the MC the driving force, otherwise it may appear the MC is being guided into the plot instead of leading it. Perhaps after the MC is attacked he realises that the demons will never leave him alone because they sense a weakness in him. This motivates the MC to seek out others who can help him realise his full potential, defeat the demons and achieve his true goal which is to live a normal life. Perhaps he never really wanted to be an exorcist?
