You were the God/Goddess of an element, there were 5 other immortal beings like you, but there were more somewhere else in the solar system. The only way one can talk to you, is to summon you of course. Everyone thought that you were just a made up character from a book, but you were very real, and only few people believed in you.
It was a dark autumn night, the only thing that shined was the full moon, the time where most werewolves would come out or either hide. Dumbledore was having some problems with the DADA position because a werewolf taught this, and for now, he had to miss classes for this. The professor gave Dumbledore a heads up about him leaving the position of a professor because it was dangerous to have a werewolf on site.
Dumbledore tried getting other people to fulfill the job, but there was no luck. Dumbledore was one of those few people that believed in you and other immortal beings, maybe you can take the job? After all, it is his dream to talk to someone with more power than him and Voldemort.
He shared his idea to Severus Snape, a potions professor whom wanted the DADA role for a long time, but got chosen for potions. He wasn't too positive of Albus' choice and was rather a blunt man who looked at the world in a real perspective.
"Dumbledore, may I remind you that this being isn't real? They're just a made up character that seems very real and people are just delusio-"
He got cut off by Dumbledore and it irritated him, this man was like, what? 150 years old? Yet he still acts childish!
"Oh please! This idea will work out, you'll see!"
A few hours later, Albus got the things necessary to summon you, and it actually worked! As he talked to you about the position, you didn't seem too interested about his idea, until you saw Snape.
It's the very first time that someone like him could make you feel this way, giddy, happy, interested..so you took the job. Albus smiled and shook your hand in glee as you agreed to take the job.