Lucas's last visit to the human realm was 1200 years ago, he came to clean up some 'flies'. There was a civil war between the demon lords; many escaped by going to the human realm, and Lucas's job was to kill them. During his clean up he meets a few humans who helped him to kill the demons he can call them his friend or a comrade he even told them his real name indicating his trust towards them. There was a woman in this comrade circle who was obsessed with fire magic and pretested Lucas to teach fire magic in the end he taught her magic when he finish his clean-up that woman accidentally killed a person who had a blessing of a War God. This angered the war God and he sent down his apostles and saints to kill that woman when Lucas need to go to Underworld since he finished his job he need to report it to the ruler, Lucas thought the woman died but now he changed his mind. The woman in front of Lucas is his one and only student. Since his student didn't find out who Lucas is he decided to no longer play the 'Lucas' role.
"Eh~ I thought the War God killed you, it appears I have mistaken."
There was a silence between them and Lucas's posture changed from a gentleman to a person who sits on a throne, his legs crossed, chin resting on one of his hands and the other playing with a pocket knife from who knows where it came from and a smirk on his face.
"...Master...You! How did you come here? No, Why are you here?"
"I was bored and came here also I want to visit some places like that Forbidden region it sounds interesting."
May and Lucas talked with each other more like May forced Lucas was forced to listen to her rambling, but Lucas learned a lot during their conversation.
"So all the classes will start two days later by the time to get along with the teachers and please don't teach magic in the same way you taught me."
"How did I teach you?"
"You don't remember?"
"No, I don't"
"You threw me in the middle of a volcano and said the temperature of my fire should be higher than the temperature of the volcano, then again you threw me in the middle of the ocean and said I should vaporize all the water."
"...What's wrong with that...?"
"EVERYTHING IS WRONG!!!" May shouted and throw a book at Lucas
"Study it before teaching the students and now please leave."
The book has titled '100 way to teach students' Lucas muttered whatever and went out.
"Damn it, Simon, I told you to get a Demon Lord who is stronger than you and is neutral towards humans but why did you get Master? What if he gets a wing of what's happening here...tsk I can't let him know."
May didn't know she would soon regret this decision in the future.