Satori: How do you intend to complete that goal, you can barely stand.

Y/N: Of course you think so but I can defend myself quite well, I was one of the few survivors of Suika's massacre, a total of 3 survivors while those who didn't fight stayed hidden.

He responded back to her with a serene expression, unfazed by what she said. Knowing that he wasn't lying, Satori couldn't help but give him a sad look, knowing that it would leave a scar in one's mind.

Y/N: Anyway, those were unexpected guests but they could become useful.

Koishi: Useful?

She asked with a certain interest. All that was left was their bodies with no souls left, nothing can be done with only corpses so why was he saying that they could become useful?

Y/N: I'll need the both of you to turn around for a bit though, no need to show you the procedure.

Koishi: Hm? The procedure?

Y/N: ...

He stepped closer to the oni's body and plunged the blade of his weapon inside its belly, the smell of blood tainting the air slowly. Satori quickly averted her gaze but Koishi did the opposite and kept looking at the movements of the man.

Y/N: Done.

He snapped his fingers the bodies vanishing and a book replacing their corpses soon after. Inside the palm of his hand, the heart of the youkai was beating at a regular interval, even though nothing was connected to it.

Koishi: Wow, how did you do that?

Y/N: I don't do anything, the library does.

He quickly answered her question, turning around to go in the back of the library. Satori noticed his movement and tried to stop him.

Satori: You can't stay here, this place is dangerous for someone like you.

Y/N: Hm?

Satori: You're clearly at your limit, at least allow me to bring you somewhere to rest.

Y/N: I appreciate the kindness but I can't accept, you could just be plotting to murder me in my sleep.

He might have accepted their presence here but he still couldn't trust them, they are outsiders and they could try to kill him for all he knows. For that reason, he refused the offer with a firm decision.

Koishi: What are you doing with that heart?

Y/N: ...You shouldn't know.

He refused to answer but Satori knew what he was about to do, his mind was betraying him and she could read it like it was nothing. She looked at the man with horrified eyes and ran to him, slapping the heart out of his hand.

Satori: You can't do that!

Y/N: Huh?

Koishi: Hm? What was he doing?

Satori: That's the reason you are cursed by youkais, you ate the hearts of those you killed inside that library.

Y/N: I forgot that you can read minds, quite a nuisance.

He didn't even bother to pick up the heart on the ground and crushed it under his foot, blood splattering around it. The youkai beside him was neutral towards his movement while the one with green hair was still standing on the sideline.

Y/N: So what? Yes, I do eat their hearts but why do you care? It's not up to you to tell me how I should live.

Satori: ...

Y/N: I told you that I would bet my life to make my goal become real, even eating people's insides.

Koishi: What? Why would even eat someone's heart? Is it even necessary?

The man turned to face her.

Y/N: Don't have a choice if I want to stay alive.

He showed them the book that they both knew, his own book. He opened it to the very first page and showed them what was written on it. Nothing was changed from last time but it was also what he needed them to see.

Y/N: Starvation doesn't allow my body to recover on its own, as long as it is affecting my body, I have to go to extreme length to recover the energy I lose during fights.

Satori: But there's other ways than just devouring someone's heart.

Y/N: I would have taken the alternative if I could but I can't leave the library.

Koishi: You can't leave the library?

Y/N: It's a little complicated... Think of it as bubble in space-time, the library exists with its own rules and one of those rules is that a librarian can only be killed with wounds during combat, not starvation nor thirst.

Satori: So you are immortal in this place.

Y/N: As long as I don't inflict a deadly wound to myself, it is the case. However, my body is still lacking the substenance that a human would need.

He glanced down at the book once more and they both looked at the words written on the page.

Y/N: Now, what do you think would happen if I left the library, a place where one cannot die from hunger or thirst to a place where one can? The result is obvious, I would drop dead on the ground the moment I take a foot outside.

Satori: So you can't go look for food.

Y/N: Yep, going outside is just a quick way to end my life.

Satori: ...

She left in her own mind, thinking of an idea. Fortunately, it didn't take her long to figure out what to do and looked at her sister.

Satori: Koishi, could you please stay here?

Koishi: Why?

Satori: I have to go do something, I will come back soon.

Without letting her sister respond, she flew to the entrance and left through the door, exiting the mysterious library. The librarian sighed and looked at the one who remained with him.

Y/N: I don't know what your sister is trying to do but I'm letting you know that I'm still not trusting the both of you.

Koishi: I know, you told us that before.

She smiled with those words, not minding his distrust at all. Her smile forced the man to look away.

Y/N: What do you want?

Koishi: Your friends, do you know how to bring them back?

Y/N: Of course I do, the library told me.

He answered with certitude, showing her that he knew what he was doing. She tilted her head to the side in wonder and asked him how he planned to do such a thing.

Y/N: The book tells me to collect some ingredients for me to reach my goal.

Koishi: Like what?

Y/N: Can't tell you that.

It was an immediate response, showing her that he wasn't trusting her for even that. His hostile tone passed through her mind and was ignored, her mental system not working and not allowing her to understand that he was being hostile.

Koishi: How are you going to get the items that you need if you can't leave?

Y/N: *Sigh* I can only wait and pray I'm afraid.

He weakly answered, knowing that it probably wasn't the best plan to take but he didn't have a choice, he was forced to do so. Taking note of his plan, the youkai nodded to herself with an ominous silence. Y/N paid it no mind and sat on the ground, resting for a minute.

Y/N: So, what do you think she went to do?

Koishi: Hm? I dunno.

She innocently answered, shrugging in addition to her answer. Having a feeling that she wouldn't provide any new informations for him, he looked back to the door and ignored the presence of the girl.

Koishi: How are you going to do this alone?

Y/N: Hm?

He gave her a quick glance. Staring back at him with her hollow eyes, she repeated her question with no hesitation. The librarian looked at the ceiling far above their heads and pondered on the question given to him.

Y/N: Just get what I need, I can't do less than that.

Koishi: ...

Y/N: Plus, I have to do it, I wouldn't be able to face the ones I love in the afterlife if I failed.

Koishi: Aren't they books though?

Y/N: ...True but I would like to think that they are more than just a cover, only existing to collect dust.

He silently grabbed a book in the bookshelf next to him and showed the girl the cover of the book to her.

Y/N: As far as I know, they are still alive. Those who perish inside the library do not follow the rules that they should follow outside of this place. With a little bit of magic, I can revive them like they never died.

Koishi: Woooow, that's amazing!

She responded with wide eyes, not understanding what the rules of this place were completely but enough to be left with amazement. The man nodded and shoved the book back in its place, leaving his hand on the side of the cover with a little hesitation.

Y/N: That's why I keep fighting, I know for certain that they can be brought back, I just have to keep going until I reach my goal.

Koishi: ...

The outsider tilted her head to the side and placed her left sleeve covering her hand under her chin. In her eyes, it looked like a reckless ideal, reckless enough to make him think that something as convenient as bringing someone from the dead could be possible. Yes, Hell, Heaven and the Netherworld are a thing inside Gensokyo but once a human lose their life, they cannot be brought back to their previous body.

...But, this library has its own rules so maybe, just maybe, something as impossible as this could be a reality.

Koishi: I want to see it too!

Y/N: Huh? See what?

Koishi: See if it works, if you can bring people back to life of course. It sounds fun and interesting.

Y/N: ...

He squinted his eyes back at her before rolling his eyes, thinking that her optimism would dissipate after a day or so. Ignoring her, he clapped his hands together and left one of them open. Soon, a book emerged from the endless library around them and landed in the palm of his open hand.

Koishi: Hm? What is that?

Y/N: The book that will guide me to my goal.

The question answered, he took a peek inside the grimoire and with a moment to himself, he glanced at the one by his side.

Y/N: Say, do you know a lot about the world outside this door?

Koishi: ...Maybe, why do you ask?

Y/N: ...No, nevermind.

He closed the book and slid it between his body and his right arm, done for today. His soulless eyes returned to the main door and he sighed another time.

Y/N: She's back.

Koishi: Hm?

The front door opened and the bell echoed inside the library.

???: Intruder detected inside the library! Satori Komeiji, proceed with caution.

Satori: ...

She stepped closer, carrying with her a small box in her hands. Approaching the man with quick steps, she gave him what she was holding between her fingers. Not saying anything to her, he accepted the gift before giving her a confused expression.

Y/N: A box?

Satori: It's easier to carry something for a long distance with one.

Y/N: ...I guess, not like I've ever stepped outside of this place.

He opened the top and his eyes were greeted with a tea set and cooked meat. He slowly placed it down on the ground and took everything out of it, placing it on the cold floor. Satori silently took the container back, glad to see that he was accepting her gift.

Y/N: What are you doing?

Koishi: ?

Satori: What do you mean?

Y/N: Sit down, I ain't eating it unless one of you take the first bite. It could be poisoned for all I know.

Satori: *Sigh* You truly are paranoid.

The sisters sat down as well and took the initiative. With the signal clear, he served himself a cup of tea and quietly drank it in the cup that he took. Satori stopped and observed the man in front of her eyes while Koishi was happily eating the food in front of her.

Satori: Koishi, please leave some for mister Y/N.

Koishi: Sorry.

Satori: Is the tea to your liking mister Y/N?

Y/N: I never had tea before, I've only heard about it in books. It's... something.

He gave it a quick glare.

Y/N: It's sour, is it supposed to be this way?

Satori: It depends on the sort of tea.

Y/N: True.

He emptied his cup and began taking pieces of meat from the utensils that Satori gave him. Under the gaze of the Komeijis, he silently ate it with a hollow gaze, no reaction coming from him while doing so.

Koishi: I think he doesn't like the food.

She whispered to her sister, still keeping her creepy smile.

Satori: ...

The one with her third eye still opened took a peek inside his mind and it was confirmed, he hated the food but he still forced himself to finish everything.

Satori: You don't have to eat it if you don't like it.

Y/N: Hm? Wasn't it your goal?

Satori: Huh? I mean, yes but I can't force you-

Y/N: It's fine. I just... wasn't expecting food to be so horrible to eat.

Koishi: Horrible?

She took another bite.

Koishi: It tastes great in my opinion.

Y/N: ...Maybe it's just me then.

He averted his eyes from the scene in front of him. If it really was a problem from his side then it wasn't worth doing this, that was his train of thought. Of course, the one who can read his mind stopped him before he could do so.

Satori: Maybe it just isn't the type of food you like.

Y/N: ...

Koishi: Did it solve our problem?

Satori: I don't know.

Y/N: Only one way to figure out.

He called his own book with a quick whistle and it flew to his side like a faithful companion. The librarian thanked the book with a smile and held it in his hands, looking at the first page of his own story.

[Y/N L/N]

[Level: 20]

[HP: 468]

[Stun Resist: 103]

[Passives]

-Extreme Fatigue: Begins battle with 25% HP (Cannot exceed 25%).

-Curse of the Youkais: Begins battle with 10% of their HP after effects are applied (Cannot exceed that number).

-Grief: Begins battle with 25% Stun Resist (Cannot exceed 25%).

-Librarian: Strength, Defense and Evasion increased by 10% while fighting inside the library.

-Lone Fighter: Evasion increased by 10% while fighting alone.

Y/N: Hm, I guess it improved a little.

He shrugged at the result, not minding it at all. He continued finishing the food afterwards, leaving nothing behind along with the tea. At the end, he gave the sisters the tea set and the plates used for the meat that Satori brought here.

...That was where that exchange ended, Y/N refused to leave the library and Satori was forced to leave after seeing that he wouldn't change his mind.

Koishi: See you tomorrow mister Y/N!

She waved back at him with a wide smile, to which he replied with an exasperated sigh. She closed the door behind her and the silence of the gloomy library returned, the shackles of the man's mind trapping him inside the room that forced him to see his friends die.

Y/N: ...

He remained still, his hollow eyes staring at the now closed door with a dreadful silence. He turned around, only greeted by the silence of this place.

Y/N: ...

He walked away from the entrance, deciding to spend his time sleeping instead of facing the cruel reality that allowed the ones he loved to perish mercilessly. He remembered their screams, their faces filled with tears of fear, they were all screaming his name yet he couldn't save any of them.

...He was a coward, a weakling that couldn't do anything and he was now paying the prize. He didn't want to die and now, he received his wish at the cost of everyone's life. However, he changed his mind, he would prefer a world where all of them except him were alive and he began his journey to make that possibility a reality.

One day, he hoped that his wish would become reality once more. For that, he needed to be strong and remain undefeated, even at the cost of bringing strong opponents inside the library.

...

...

Meanwhile, in the dark of a room, a woman was laying on the cold floor of her house with gritted teeth, her hands placed under her head and using her arms as a pillow. Long gone in her destructive thoughts, her eyes were staring at the ceiling, remembering the humiliation she received a few hours ago.

???: Tch, I'm gonna rip her head off next time!

She exclaimed to herself, swearing vengeance to the one who defeated her. Her long and white hair was spread everhwere around her, her red and white bow in her hair forming a small crown now that she was on the ground. Her white shirt was torn apart from the hits along with her red overalls.

...Fujiwara no Mokou was a force to fear in this world. With her undying body inside the laws of this place, she could fight until her body would become numb to pain, a deadly opponent to face in a real battle. However...

Mokou: She's gonna get it next time, I'll turn her ridiculous black hair into flames!

She was currently complaining about her eternal rival, the princess of the Moon who decided to run away, leaving the eternal flame of hatred inside her heart. She punched the floor beside her and a loud bang echoed, holding just enough strength to not break it.

Mokou: ...

She wished to see her pay for everything she did. That flame inside her heart would not vanish otherwise and she knew it, she would never forgive her. It was her strongest desire, overcome her power and crush her for the last time.

Mokou: ?

Her dark thoughts were stopped by a piece of paper flying inside her room through the open window. It flew delicately before landing right next to her, forcing her to get on her knees to pick it up.

Mokou: What's this about?

She doesn't remember the last time junk flew inside her house due to the wind, it was forever ago. She wanted to discard it as another piece of trash coming from the outside world but she stopped herself from burning it when her eyes quickly read her name at the top of the paper.

"Fujiwara no Mokou, the girl that was once human before becoming a monster of flames. Her desire being to make princess Kaguya pay for the crime of laughing at her long deceased father with her impossible request. The girl with white hair now longing for revenge and hatred inside her broken heart.

With this, a proposal was given to you. One knows that someone who drank the elixir cannot be killed inside the world of Gensokyo and the outside world. However, you have been granted the chance to accomplish that desire, to reach the knowledge that will show you how to reach that goal.

However, you will be tested. To begin your trial, go underground and search for the door that will lead to your goal. Being victorious or a doll to those who defeat you, you shall decide your fate."

Mokou: ...

She was speechless. She wanted to toss it aside, pretend that it was a lie but the shock that she felt when reading those words was real. She felt a strange aura from the words that were inviting her to search for her very own answer.

Mokou: ...Heh, what a bunch of bull, no way something as convenient as that would exist.

She tossed it aside and turned her body to the other side, her back facing the piece of paper. As much as she would like to ignore it, the seed of desire was planted inside her mind and she would soon meet her demise like the many others who tried to reach the knowledge beyond their power.