Fantasy Assassin in a modern world

Loki was in his room looking at the scroll he got from Tang Ao. Loki chuckled as he remembered how he got the scroll. Once Tang Ao finished his talk with Michael he 'accidentally' bumped into Loki. After they bumped into each other Loki started a conversation which he led into Tang Ao giving him a basic martial art technique. 

Loki already confirmed that there was indeed a new form of energy within him. It was the same impure energy that the people of this world called inner energy. It was weaker than mana but it was more abundant than it. 

'Is it possible to make this inner energy purer?... I guess I should review that later once I get a better feel on how to control it.' 

Loki then studied the martial art technique that Tang Ao gave him. It was a simple technique in which the user gathers his inner energy into his fist or legs to unleash beyond human strength for a few seconds. It was basically the same as his [Enhancement] spell but less versatile. 

Loki stood up and did what the scroll instructed and with his skills and experience with mana, it was easier for him to learn the technique than those newbie martial artists. The consumption of inner energy was minimal and this could be something he can use during emergencies when he was out of mana. 

After testing the technique a bit Loki felt his body become extremely heavy and lay on his bed. It was then he realized that his inner energy was nearly depleted. 

'I see, so this is the backlash of using too much inner energy... It's rather similar to the backlash from consuming mana, but instead of mental exhaustion, it's physical exhaustion. I need to keep that in mind when I use it next time.' 

...

A couple of days had passed and nothing major had happened. Loki continued to meditate in the library, but unlike before he was now not only trying to increase his mana but also a bit of his inner energy.

Another thing different from before was that Michael was now a frequent visitor of the library as he continued to read the books on the occult. Unfortunately, his mana supply wasn't enough for him to see the necessary books to activate the system. Still, Loki wasn't worried for as long as he continued to stay in this library Michael would someday grow strong enough to be able to read the true grimoires. 

As the days passed by Loki finally realized that it has been a while since he did a job from his true occupation. It was then he remembered that he hasn't established a way to contact him in this world.

'Damn, I forgot about that. This world has a different way of finding people, if I do the same thing as I did in the previous world I'll get caught for sure. On the other hand, if I just wait for jobs to come my way it might take forever... I wonder how can I get clients without anyone finding out who I am?...' 

Loki started thinking of ways to deal with his problem, but after a while, he gave up as he knew too little of how this world works. It was at that moment he had an idea, if he couldn't think of a way, didn't he know someone that could.

...

Harold was unconsciously smiling as he put down his phone. He had just received a request from Loki. Ever since he met the assassin the boring days have long gone. Though it was dangerous every now and then, but the danger was part of the thrill.

'So he wants me to send a message to the people that he's now taking assassination jobs. Since he's very hot right now the moment I post anything regarding him many of those hidden forces will flood the site and try to locate me. So I need to hide it well enough that they won't catch me, but it must be visible enough for people to see it. Heh, this is going to be quite fun to do, first I should make the website.' 

Harold started typing on his keyboards with extreme concentration. While he was typing Loki had sent him a message. The message was about the rules for the clients. 

1. I will only kill those that cannot be handled by the law.

2. The reason for wanting to kill must be just. 

3. Depending on the reason the payment will be different.

4. To those thinking of capturing me or attacking me, I advise you to think twice. I will retaliate and the consequences for tricking me will be intense pain.

Those were the rules Loki set up for an assassination job. Harold became his middleman as he was going to control the website. One mistake and both he and Loki would be found out, and worst-case scenario Loki's enemies would kill Harold. 

'That just means I shouldn't make a mistake Wait... Maybe I shouldn't make a website and instead, find those people that fit Loki's requirements myself.' Harold smiled as he started to move his hands. He was still afraid, but at the same time, he was excited. 

"First, I should try a test run." Harold hacked into the police station's server, once he was in he started looking for people that fit Loki's preferred client.

...

A father sat in the corner of a dark room, he was holding the picture of his lost child, and at the ceiling, there was a noose. The father looked at the picture of his daughter and started crying. 

"I'm sorry, Emily, papa can't find you. I tried my best but no one would believe me. No one would even listen when I said that they took you from me... I'm sorry that papa was so weak and useless... But do not worry, you and papa will meet again." 

The father who could not find his daughter stood on a chair and was going to put the noose on his neck when he suddenly received a message. It was from an unknown source, he was going to ignore it but then he saw a familiar name, Fade.