Fantasy Assassin in a modern world

The moment the leader of the students from another school threatened to hurt his siblings, Loki could not stop himself as he started to emit a bone-chilling killing intent directed at that person. No one else was able to sense it but the leader of the group of students. The moment he sensed Loki's killing intent the student knelt on the ground trembling in fear. He could not understand what was happening to him, but after a second the intense fear he felt suddenly disappeared. 

Loki was able to calm himself before he did anything, in fact, he almost killed the student standing before him. Loki truly wanted to tear him apart, for daring to threaten his siblings, but, he knew that doing so wasn't something his siblings would want. 

...

Since no one else felt the killing intent Loki emitted, everyone was confused as to what happened to the student. Even Shin wasn't able to perceive what just happened, but his instincts were telling him that it was Loki that had done something. This, of course, made Shin even more excited to reach the day that Loki finally accepts his challenge. Once the effect of the Killing intent disappeared the student was able to stand up. 

"Are you okay?" One of the student's companions asked, but the leader of the group was still in a daze and did not respond. 

"So is that it, are we done here?" 

"..."

When the group heard Shin's question they looked at each other unsure what to do. The only reason they came here was because of their boss who wanted to get revenge for his little brother. They didn't really have any grudge against Shin, not to mention without their boss they wouldn't be a match for Shin as most of them were just rank two martial artists. 

Seeing that the group of students didn't know how to respond Shin couldn't help but sigh. He didn't know what happened to their leader but it was obvious that the person was unfit to face him now. 

"As I said before, you guys better come back some other time. Don't worry I won't run away from any battle so here tell that guy he can contact me on this number. He can tell me when and where he wants to fight and I'll be there."

Shin took out a pen and paper from his bag and wrote a special phone number he uses for those who wish to challenge him. After he was done giving the number to one of them he, Loki, Alisa, and Liam left. 

...

"What was that all about?" Liam whispered. 

"How should I know?... Still, Shin is famous for having fights with anyone that's willing. It's obvious that those guys came for revenge." Alisa answered while glancing at Shin who was walking behind them. 

Alisa and Liam then continued their conversations on rumors about Shin. After a while, Alisa suddenly pulled Loki into the conversation. 

"What do you think about that big brother, is that rumor true?" 

"Why are you asking me? How about instead of asking me, you just ask the person in question directly. Hey, Shin, I'm sure you heard that conversation of theirs, so is it true? Is a beautiful woman chasing after you and you actually promised to marry her?" 

"You guys are talking about Haruhi, I guess that rumor is sorta true."

"Huh, what do you mean sorta true?"

"You see when we were little our parents came to an agreement that we would be betrothed. For some reason the first time we met she said that she didn't want to marry me, and I felt the same way. So we told our parents about it and the engagement was easily canceled. I thought that would be the end of that, but for some reason, after some time Haruhi actually confessed her love for me and wanted to be my girlfriend. So I told her I wasn't interested, as I was more interested in fighting and getting stronger than playing lovers. She then challenged me to a fight and said that if she won I should become her boyfriend. I of course, as per usual accepted the challenge. We fought and she lost. After that, she promised that one day she would surpass me, and then I would become hers. So every several months she would come to challenge me to a fight." 

Loki, Alisa, and Liam were amazed by what Shin said. They were already expecting him to say that rumor was a joke, but it turns out that it wasn't. Some girl out there actually likes this battle-hungry person. The siblings then looked at Shin with dumbfounded expressions.

'Well, I guess he is sorta handsome, and some girls do like powerful men.' Alisa thought as she looked at Shin's muscular body.

...

After that shocking revelation, the trip to the house became oddly quiet. When they finally reached their house, Loki looked at Shin. 

"This is our house, so this is where we part." 

"I see, thanks for the meal Sir Loki, see you tomorrow." Shin waved his hands as he walked away. Liam and Alisa waved their hands in response. Once Shin took a turn in the street corner Liam and Alisa entered the house while Loki remained outside. Loki looked in the direction where Shin went and sighed.

'I guess, I am technically responsible for his safety since I invited him to a dinner outside.' Loki went to his room got changed into his Fade look, and headed out to follow Shin. 

...

After parting ways with Loki and his siblings, Shin took out his phone and sent a message.

'Hey, I want you to buy me a house, near this location.' After sending the message he got a quick reply. 

'When do you need it?'

'The sooner the better.' 

'As you wish, young master.' 

Shin placed his phone back in his pocket and when he looked at the road ahead he saw someone wearing a white mask and black trench coat blocking the path forward. 

"That's a nice costume, among the Fade cosplayers yours looks high quality. So anyway, seeing as your blocking my path, I'm guessing you need something from me, right?" 

"Mugami Shin, you have done numerous evil deeds and I've been hired to eliminate you." The person spoke in a low tone as he took out a dagger from his coat. 

"Oh, is that so? Then that must mean you're not a cosplayer but the real deal, is that correct?" 

The person who looked like Fade did not answer as he took another dagger out while emitting killing intent.

"The silent treatment? Come on now, since you're going to kill me and all that, why not answer the question?... Fine, since you don't want to answer I will answer for you. You are not Fade, I've seen the real deal and you're not remotely close. True that your costume looks the same, but your aura is different. The real one doesn't emit any kind of aura, even though he's standing right in front of you, it's as if he isn't really there. Not to mention he has that overpowering killing intent of his that could suffocate you.. On the other hand, your killing intent isn't even lukewarm compared to the real thing. So let me ask you a different question if you're not Fade, who are you?"