Fantasy Assassin in a modern world

Loki sighed as he sat back down and started to think about the pros and cons of having the supposed system. One of the biggest pros in gaining the system was access to the Akashic Records and gaining skills from its infinite library. He would be able to go beyond his past self's level of power. On the other hand, the biggest con will be being a part of such a large-scale event. As an assassin being in such an eye-catching role was not something he wanted. 

If the spirit of the Akashic Records was saying the truth and that it was attacked by an entity from another universe then something big was going to happen. He might be accepting a job that was way beyond his level of expertise. 

'Still, this person has given a request for aid, though it's not an assassination job. I wonder what would you have me do, Shera...' While he was thinking so deeply he suddenly heard a voice whisper in his ear. 

Loki's reflexes kicked in and he was about to subdue the person who whispered, but when he saw in the corner of his eyes that it was Alisa, he quickly stopped himself. So instead of attacking, Loki's body jolted as he looked at Alisa in surprise. 

"Why did you sneak up on me like that?" 

"I didn't sneak up on you. I just came in normally, but when I called out to you, you didn't respond at all." 

"Oh, I see... So what are you doing here?" 

"I came here to pick you up." 

"Pick me up?" When Loki heard what Alisa said he looked at the clock and saw that it was already four p.m. He was in a dazed state as he didn't notice the time passing by. He was sure that when he started speaking to the Spirit of the Akashic Records it was one p.m. It didn't feel like they had spoken for that long. 

"Are you feeling alright big brother?" 

"Yeah, I'm alright just a little tired. Can you hold these books for me and wait outside the front gate. I need to do something first before leaving." Loki tried to hand over the six grimoires to Alisa, but she didn't take them and instead looked at Loki with a weird expression on her face. 

"What are you talking about big brother? Are you really feeling alright?" 

"Huh, why what's wrong? I'm just asking you to bring these books and wait outside." Loki looked at the six grimoires and then at Alisa. 

"You keep on saying to bring some books, but what books are you talking about." 

"Huh, of course, I'm talking about the one in my hands. As well as those five over there." Loki pointed at the five grimoires on his desk. Alisa looked at the desk and looked at Loki with a worried expression on her face. 

"Big brother, I don't see any books in your hand and on your desk. I knew it, I knew it was too early for you to go back to work. How about you talk to HR and ask for an extended leave." When Loki heard Alisa's response he finally understood what was happening. 

'The grimoires are invisible to her.' 

'Of course, they are, these books can only be seen by those who are worthy. The bare minimum requirement is the person needs to have mana, that girl over there doesn't have an inkling of mana she doesn't even have that so called inner energy the people are using nowadays. Also, don't bother bringing the books out of the library. They are bound here just like me and cannot leave. The moment you try to bring them out, they'll just return back to the shelves were you took them.' The Spirit of the Akashic Records responded in his mind. 

Seeing that her brother grew silent and was staring at empty space, Alisa was getting even more worried about his condition. 

"Big brother, are you sure that you're alright? If you want we can go to the hospital." Loki snapped out of his bewildered state when he heard Alisa's voice. He looked at his little sister that was worried for him. He smiled at his little sister to ease her worries and shook his head. 

"I'm fine, I guess I might have misplaced the ones I wanted to bring with me. So you go on ahead first, I need to do something before I leave." 

"Are you sure?" Loki sighed as he patted his little sister's head. "Yeah." 

"Big brother, I'm not a little girl anymore so can you stop patting my head?" Alisa lowered her head and looked a bit embarrassed. Seeing her reaction made Loki remember Shera.

'The two of them really do look alike. Even the way they act was somehow similar.' Seeing that made Loki feel a pang in his heart. He then chuckled and ruffled Alisa's hair even more. 

"I'll never stop doing this, it's my right as an older brother. Also, patting your head makes me feel comfortable." When Alisa heard what Loki said she lifted her head and saw a weird expression on her big brother's face. It was an expression filled with loneliness and nostalgia. 

"Big brother?..." 

"Well, anyway just go on ahead, and contact Liam as well. How about the three of us, eat out today. Let's celebrate my return to work." 

"Alright then... I'll be going on ahead." Alisa was still a bit worried about Loki's current state as she left the library. The moment Alisa left, the spirit of the Akashic Records started speaking again. 

"That's rather interesting, you can use mana but your sister cannot. You really are something special. If I was in my complete form, I would have easily figure out who you truly are, but I guess a mystery like this is fun every now and then. So what do you say will you activate the system?" 

"I don't really know if I should or not, but since you're not going anywhere, that gives me a lot of time to think about it before giving my answer." 

"Hey, my time might be eternal, but yours is finite. So how about giving me an answer now." The Spirit of the Akashic Records urged. Loki simply shrugged his shoulders and started walking towards the exit. 

"Well, that's all I wanted to say, see you tomorrow." Loki waved his hands, as he exited the library. Up until the moment, he opened the door to the exit, Loki heard the Spirit screaming at him, but the moment he was out of the library he could no longer hear the voice of the Spirit.