I’m a Teacher at a High Martial Academy

The laws of Heaven are in disarray, and the protagonist transmigrates to a parallel world. This is a world of high martial arts where magic has returned and all kinds of cultivators and people with supernatural abilities are rising to prominence. The legendary demon, devil, and insect races have also appeared, along with cults. Former tourist attractions have long since become places for all sorts of expeditions. Schools here don't just teach regular subjects. More importantly, they teach students how to wield magic in battle.

Unfortunately, the protagonist has terrible luck. He strays into the demon race's mountain wilderness, and by the time he makes it back to the human world, he's a bearded middle-aged man. He's also been poisoned by a parasite, missed every chance to improve himself, and can't find a guild that will take him. But the peak of his life is only just beginning!