basically their master was an imposter and he burned down their ministry for some kind of vessel shaped in a mirror?? i think itll be more elaborated in season 2
The master was a half demon (or something along those lines) and killed everyone to get the mirror in which another demon is sealed. The main character has a demon hiding inside him that caused all his misfortunes untill now.
what happened?? i didnt really understand so it would be greatly appreciated if someone could dumb it down for my puny brain