I Quit the Hero's Party

There was once a party who sought to defeat the Demon Lord and save the world, the Hero's Party. However, tired of the Hero's Party unwillingness to go directly after the Demon Lord, the Ashen Wizard Raniel quit the Hero's Party and returned to his hometown to meet with his master. There, he was recommended a position as an assistant professor at a prestigious academy.

"Why are you so bad at this? Just make circuits, cover yourself in mana, and use it."

However, a genius like him didn't seem to have any aptitude for teaching others...