Radiant

A brief description of the manga Radiant:

Seth is a young student of the sorcerer from Pompo Hills. Like all sorcerers, he’s “infected.”
He is also one of the few people who have survived the encounter with the Nemesis, creatures who came to Earth from heaven and destroyed everything around them.
Because Seth has immunity against the poison Nemesis, he dreams of becoming a Hunter and fighting the Nemesis.
In fact, however, Seth’s true purpose is to find the “Source” where the Nemesis came from. Under the close supervision of the Inquisition, together with his friends, he sets out to find the “Source”…