Fantasy Assassin in a modern world

When Michael arrived at school many people were looking at him strangely. He was confused as to why he who was usually invisible in the eyes of others suddenly become someone they found interesting. As he continued to walk towards his classroom some of the students finally decided to approach him. 

"Hey, you're Michael from Class 1-C right?" 

"... Yes..."

"So it really is you!" 

When the other students heard Michael's confirmation they started swarming the confused Michael and bombarded him with questions. 

"Is it true that you're friends with Shin?" 

"Did you and Shin beat up Hayate's group?"

"Why were you the only one who wasn't detained?" 

"Did you get to see the soldiers of the Elite Dragon Brigade?" 

"Is Hayate really as powerful as they say?" 

Michael was overwhelmed by the questions and couldn't respond, but now he understood why everyone suddenly took interest in him. It was regarding the incident last night, even though there was no news about it, nor did anyone leak it, but the kids in this school especially those of the martial arts course were from powerful and wealthy clans, so gaining such information was easy for them. 

As Michael was continuously being surrounded by the students and asked numerous questions which he could answer the bell rang. Even though the bell rang the students ignored it and continued asking questions. It was then that the students noticed an approaching teacher coming by. Seeing the teacher the students reluctantly went to class. As for Michael, he was called by the teacher telling him to head to the Principal's office. 

...

The conversation Michael had with the Principal was a quick one. The Principal basically told him not to tell anyone of what happened last night, and that Hayate's clan would come later after school to compensate him. 

Michael left the Principal's office still in a state of shock, there were too many things happening. He was still trying to calm himself down from what happened yesterday, and now all of these happened.

Yet among all of the weird things he experienced, what surprised him the most was that a powerful clan like the Mutou Clan was actually willing to compensate him. As for not telling anyone of what happened last night, well he didn't even tell his parents so why would he tell anyone else. 

...

While Michael was heading to his classroom, Loki was meditating inside the library gathering as much mana as he could. In this entire city, the library had the densest gathering of mana, it was the best place to increase his strength. He could already feel his mana supply increasing.

'This place truly is the best place for me to grow, the only problem was the noisy spirit in it.'

"Hey, I know you can hear me why are you ignoring me?! HEY, HEY, HEY, HEY! Why are you still trying to increase your mana supply this way? If you become the host of the system I created, you would quickly improve and won't need to do such tedious things like this." 

The Spirit's voice resounded in Loki's ears and continued to talk despite Loki ignoring it. If it were anyone else, they might have given up and left the library, but Loki's mental fortitude was high due to his training when he was younger.

Yet even though he can ignore the spirit and continue to train, he still found the spirit quite irritating, but he could not do anything about it. The only way to make the Spirit shut up is if he becomes the host of the system or if he left the library, neither of which he wanted to do. 

Time passed as the Spirit continued to annoy Loki by shouting, but Loki didn't even flinch as he continued to absorb as much mana of the world that he could. It was then someone came into the library and it wasn't his sister. Loki knew exactly who the boy was as he had just saved him yesterday.

...

The moment lunchtime was about to begin, Michael noticed that his classmates were about to surround him. Yet Michael who was sitting at the back of the class was close to the door, so the moment the bell rang he quickly moved and was about to escape. 

The other students who noticed what Michael was planning used their inner energy to intercept him, but to everyone's surprise and even to Michael's surprise he was moved faster than any of them and escaped.

Ever since he was rescued by Loki for some reason Michael's body felt lighter and he was able to move better than before. Still, he had no time to be surprised by his increase in speed and started running towards the library. 

...

Michael who had shaken off his pursuers was now standing in front of the school's library. He had been in Sekiko Academy for several months now but this was the first time he ever came to the library. He never thought of going to this place since there were no martial arts techniques to be found here, the most they had were basic skills for people without any inner energy. 

When Michael entered the library he felt something flowing into him, it was a rather pleasant sensation. He looked around and noticed that there was no other student in the library and the only other person here was the librarian. He approached the librarian who was smiling at him. 

"How can I help you?" 

"Ummm... Do we have any books regarding the occult?" 

"Of course we do, we have dozens of them what do you like to read?" 

"I'm not really looking for anything in particular, can you recommend me some?" 

"Of course, just wait a second." 

Loki then went under his desk and took out the books he already prepared just in case Michael did come to the library. There were books that could help him start his journey in discovering mana, as well as the hidden books that could activate the system. 

Michael was surprised at how fast the librarian found the books, it was as if he had prepared them beforehand. The thought passed through Michael's mind for a second but quickly went away as he wanted to start reading the books given to him, so he went to a corner of the library and started reading. 

....

Loki was smiling as he watched Michael reading the books he gave with great interest, as for the Spirit it became quiet. 

"So what do you think, is he worthy?" Loki spoke softly. 

"... He does have the potential, but he is nothing compared to you." 

"Who cares, unlike me, he might be willing to do what you want." 

"Hmph, so this was your plan all along... Well, it doesn't really matter if he has the potential to activate the system if he can't read the books that could prove him worthy."

"We shall see, you better pray that he could activate it, cause there's no way I'm going to activate that system." 

...

While Loki and the Spirit were talking Michael was engrossed in his reading. Just reading a few pages of the first book, he understood that there was a different form of energy that was called mana. It was similar to inner energy but aside from using one's own energy mana also uses the environment's energy. 

'If I can somehow harness this mana for myself, then I can finally be able to keep up with the others and make my parents happy... But how to start, how do I gather mana?'  With his renewed vigor Michael started reading the book faster than before.