With the dawn of a new day, the being of hatred and flames emerged from her painful slumber. Unlike others, sleep was not a need for her. In fact, nutrition and water was also not necessary for her, her shackles were removed at the cost of her title as a "human". Now, the human that Mokou once was perished, replaced by this version of her. With no proof of her existence, she vanished and arrived at Gensokyo.

Mokou: Huh...? Morning already?

She mumbled under her breath. She had no reason to sleep but yesterday's beating was enough for her to collapse on the cold floor. Due to her indestructible body, she was not afraid of death, it was a concept that she would never experience in her life. She became like this for a reason that was beginning to fade away, she would sometimes stop and ponder, only to remember after a minute or so.

...Her purpose was hazy by times, but seeing her eternal rival would always bring it back in her mind, the reason why hate was overflowing her core.

Mokou: ...Well, would you look at that.

She whispered to herself, her gaze fixated on the paper beside her. She simply assumed that it was part of yesterday's nightmare but she was forced to accept that it was real. The invitation was still waiting for her response, promising her to give her what she want to know. Still sluggish, her arm lazily reached for what she first assumed to be junk and glanced a second time at the letter.

Mokou: ...

She could accomplish her revenge if what it was saying was true. The only thing it told her was to look for a door underground. Even if she couldn't find it, it would be a nice change of scenery for once. She stretched her legs and stood up, deciding to take a look at what this thing had to offer.

...

...

Y/N: *Yawn*

Meanwhile, inside the dilapidated ruins that the proud library once was, the only librarian residing inside woke up from his slumber, his head pressed against the cold desk that quickly became warm after leaving his cheek pressed against its surface.

???: Hey mister Y/N!

Y/N: ?!

Startled by the voice calling him, he turned his head and recognized the familiar youkai greeting him.

Y/N: Koishi? How did you get here without triggering the alarm?

Koishi: What are you talking about?

She asked with utter calmness, unable to demonstrate her emotion. However, he could tell that she was confused by his question.

Koishi: That bell did ring, you didn't hear it?

Y/N: ...I guess it must be the case, sorry.

He apologized, standing up from his seat with little enthusiasm. Of course, the bags under his eyes and his pale skin due to a lack of light was making his situation worse but Koishi did not say anything about it.

Koishi: Are you going to go get what you need today?

She asked immediately, not wasting a single second. The man gave her a gloomy gaze and turned to face the desk that he used to rest, only to see a single book left there by his side. He frowned before grabbing it.

Y/N: I don't remember placing that book here.

Koishi: Hm?

She stepped closer and took a peek at the cover of the one he was holding. Her curiosity was soon replaced by a short surprise.

'The book of Fujiwara no Mokou, the pheonix of hatred and vengeance'

Koishi: I know that person.

Y/N: You do? I mean, I suppose I shouldn't assume that you only live in a cavern.

He opened the book and a black letter slid into his hand. Y/N's eyes immediately squinted, recognizing the letter that was hidden inside it.

Koishi: What is that? A letter?

Y/N: More than that, it's a death sentence.

The content of the letter was short and simple but still terrifying to the one it was aimed at.

'Y/N, the dying librarian searching for the unreachable, a guest is coming your way. Learn and fight or your wish will never become reality, you will forever live knowing that you failed to save your friends.'

Koishi: Are you alright?

The girl with green hair asked, seeing his hand tremble for a moment. Y/N dropped the message and it flew away inside the large library around them. Knowing that he had to answer her, he nodded in silence.

Koishi: So Mokou is the guest?

Y/N: Seems like it, dunno what she's like but it doesn't matter.

The both of them sat down around the desk and glanced at the first page of her book, taking a look at what the librarian will be facing soon.

[Fujiwara no Mokou]

[Level 71]

[HP: 342]

[Stun Resist: 146]

[Passives]

-Fiery Passion: Upon receiving a hit, the attacker receives 2 Burn.

-Harvest of Flames: For each hits on an opponent, the target receives 1 Burn.

-Pyromania: If the target is affected by Burn, each effects applying Burn adds a +1 to the total amount of Burn inflicted.

-Tenacity: If the attacker uses physical attacks, reduces the damages received by 35%.

-Ember of Vitality: Every 4 turns, uses a special attack. If the attack hits a target with Burn, recover as much HP as the target's current stack of Burn.

-Hourai Elixir: If HP reaches 0, has a 100% chance to revive [Fujiwara no Mokou] with 100 HP and lowers the probability of resurrection by 5% and HP recovered when revived by 10(cannot go below 1). If their HP is brought back to 1 after being revived, this effect will not trigger for the rest of the fight.

-Magic: The person is able to use magic.

-Danmaku Fighter: Increase Evasion/Stun Resist by 20% during battles.

-Flight: The person is capable of flying.

Koishi: ...It doesn't look fair at all.

Y/N: It isn't, nothing is fair in this place. If I remember right, Suika was on the same level of power and she exterminated almost everyone who faced her.

Koishi: Then how will you win against her?

Y/N: *Sigh* I won't.

The girl's eyes widened a little, the man accepted his death right in front of her eyes and knew that the outcome of the incoming battle would be nothing more than a simple beating.

Y/N: I could try calling for support from my friends but even then, I would only make them die a second time in front of my eyes, I don't think I'm ready for that.

Koishi: ...You even have a big disadvantage with your fatigue and curse.

Y/N: It reduces it to 11.7 or 12 if you want to be more approximate. A good punch would be able to kill me I'm afraid.

Koishi: ...

The youkai looked down at her own hands and fell silent, the one that would soon fight taking a second look at his future opponent. He knew that it was already over before the fight even began, that person had the advantage. The both of them were their own thoughts, forming a plan on their own as well.

Y/N: Maybe this could work...

He mumbled under his breath and glanced at the massive library behind him. Inside this place, he had endless knowledge, surely there must be something that would give him the upper hand in the fight.

Koishi: Are you going to face her alone?

She asked without even giving him a glance, her eyes vacantly staring at the books in front of her. Y/N was the one to look at her but refrained himself from saying anything back to her, an answer not needed.

Koishi: ...I see.

She knew the answer as well, even her foggy mind could perceive the obvious. She stood up, moved the chair back in its place and finally faced the librarian that will be risking his life to defend this place.

Koishi: Maybe we can do something about that curse!

Y/N: Huh?

Koishi: I know someone who can!

Y/N: You want me to trust you? What tells me that you aren't lying?

Koishi: ...You can't, I'm just telling you that.

Y/N: I guess you're right, I don't have to believe you.

Koishi: So, do you want to get rid of that curse?

Y/N: Considering that it would increase my health from 10% of the 25% of my original power, it would go from 12 to 117.

He squinted his eyes and tried to determine if it was worth the risk of getting killed once he took a step outside. He knew nothing of the world on the other side of the room and if people are as strong as that Mokou was a common thing, he would be in deep problem.

Y/N: Say, are people like that future guest common outside?

Koishi: Common? Hm... it depends, some are really strong while some are less. However, they still have an advantage against humans.

Y/N: That's bad then, maybe it was for the best that we remained hidden here.

Koishi: Didn't you say that you couldn't leave even if you wanted to?

Y/N: That's also true.

The librarian took the possibilities into consideration and knowing that his and Fujiwara no Mokou's path will cross eventually, he had to take all chances on his side. Slowly but surely, he nodded back to the one standing beside him.

Y/N: I'll take that chance.

Koishi: Really?!

Y/N: Why the surprise? I know that I have to fight her, might as well have a small chance of victory than a predetermined defeat.

Koishi: Then we should-

Y/N: But I have to go get something first.

He stood up and hurried inside the maze that this place was, leaving the girl to herself. With nothing else to do, she simply waited for the man to come back. Not long afterwards, he emerged back from the bookshelves but instead of his usual outfit, he was wearing a black trenchcoat with red outlines and a small add to it to cover his neck with the exception of the front, black pants with a black suit under the coat with crimson lines and to complete his new look, a sheathed sword was by his side.

Y/N: Alright, we should hurry.

Koishi: Where did you get that?

Y/N: ...You don't want to know.

Not answering her question, they both returned to the entrance and approached the door that will lead them outside, where their search will begin. Opening the door, Koishi happily stepped outside and turned around to the man, still standing on the other side hesitantly.

Koishi: ...

Taking a deep breath, Y/N peeked his head outside, making sure that nobody was waiting for him to step outside in order to backstab him. Of course, nobody was there so he followed her outside and the door immediately slammed shut, making the both of them jump.

Y/N: What the...

The youkai tried opening the door once more but the door remained firmly closed, like something was pushing on the other side. On the other hand, when Y/N tried to open it, it did so without a single resistance.

Y/N: I guess it's some sort of locking method... if no librarians are inside.

Koishi: ...Does this mean?

Y/N: ...

He glanced at the one who didn't finish her question and silently confirmed her doubt.

Y/N: This place will probably become permanently shut once I die.

Not in the mood to talk about his own death, the exhausted man looked around before asking the girl where they should go to leave this place. Her usual smile returned and she began leading the path to the surface, where her help will be. Their footsteps felt like they were walking on top of water, the echo that could leave one insane if forced to listen to it longer than they should.

Y/N: This place is a mess, how the hell are you able to walk around here?

Koishi: How are you able to locate yourself around your library? I think they are the same.

Y/N: ...I wouldn't say they are the same, this is an actual maze compared to the library.

...

...

The sounds of footsteps inside the tunnels underground felt like a cacophony with a certain rhythm to it, only hidden. Those sounds were coming from the woman with long white hair carefully looking ahead, expecting a random youkai to jump at her like usual. She was bombarded by them when she began her journey but it was now dead silent, no sounds except hers.

Her goal was the door that the letter mentioned. She didn't believe that it was true so she went there to prove it with her own eyes. Of course, being the maze that it was, she had to walk around for quite a bit and fought many who thought it was a good idea to pick a fight with her. Having seen much worse, she emerged victorious without a single problem, annoyed that her time was wasted for something as fruitless as that.

Mokou: Why is nobody here, this place is too silent.

It was almost like they were fearing this part of the cavern. They knew something that she didn't, they avoided this section for a purpose and she could feel it. Her blood starting to boil with curiosity, a quick grin appeared and vanished the moment after, if the reason was because of a strong youkai, she might get a more appropriate fight than the previous ones.

Yet, she will meet nothing but disappointment. At the very end of her journey, she stopped in front of the door that she once thought was a prank, closed with a letter attached to it, a letter that wasn't there when the librarian and the youkai departed. She reached for it and took a look at the content of it.

"Fujiwara no Mokou, the girl who took too long to show herself, the access has now been closed until the ordeal is ready to face you once again. However, your target, if you want to learn the knowledge that you are looking for, is currently on the surface.

Kill the librarian and the door will open."

Mokou: A librarian? Why is there a librarian hiding underground?

No answer were given to her, the letter tossed aside. She tried to open the door but it wouldn't budge, even after giving it a good punch with all her strength, not even a dent in it. She was forced to acknowledge what the letter told her and began her search, a little exercise wouldn't hurt, especially if it allows her to obtain what she wants.

Mokou: I'm gonna make that librarian spit his wisdom.

The roots have already spread past the point of return. Knowing her goal, she began her hunt with a wide grin, a smile that she once thought would never reappear on her face. Now that an opportunity to make her revenge become real, she was not going to back down so easily.

...

...

Y/N: Tch, the sunlight's too strong.

He mumbled under his breath, hiding his weak eyes from the light above them while his other hand was resting on the handle of the katana by his side. He might have accepted her aid but he was not going to drop his guard.

Koishi: Is it? I don't feel any difference.

Completely oblivious, the girl responded without understanding the reason of his complain. After spending an extreme amount of time hidden inside a dark prison, it was a normal reaction towards natural light.

Y/N: Not like it matters.

Slowly adjusting his sight, the light began to weaken and he was capable of seeing his surroundings, grass and trees all around them and a path leading outside of this small shelter of leaves towards a large plain.

Koishi: We should hurry, we don't have all day.

Y/N: Where are we going?

Koishi: Up there.

She raised her arm and pointed the large mountain that seemed to reach the skies, clouds covering the top and letting one's imagination run wild. Maybe during a cloudless day, one could finally peek at the unknown at the very top.

Koishi: I know a shrine is up there, they take care of curses and blessings.

Y/N: ...I assume they don't do it for free.

Koishi: No idea.

Y/N: *Sigh* You're not helping.

With time against them, they began their walk towards the large mountain that would provide support to the librarian cursed by the deceased youkais haunting him. Stepping into the plain, they walked straight for the bottom of the large creation left by nature and ignored the path that would have made them took awkward turns.

Koishi: Say, what will you do if they do get rid of your curse?

Y/N: ...Fight I suppose, I don't have a choice, someone placed a target on my head after all.

Koishi: Placed a target? I thought they wanted a book.

Y/N: Yes, in a way, that's what they want but the library does not reward the cowards or thieves, you have to deserve that reward.

Koishi: By defeating you? That sounds complicated.

Y/N: Defeat is a way but the guests are always asked to kill the librarians they face, it's a life or death situation for both sides.

Koishi: How do you know that?

Y/N: ...I learned the hard way, after one of my friends was ripped her arm off by a demon. It could have stopped there but decided to devour her still breathing body in front of our eyes, saying that it was told to do so.

Unconsciously, the youkai's eyebrow lowered, giving the girl a saddened expression. It was an unconscious movement that was noticed by the man, who could only look down in shame, blaming himself for the death of someone close to him.

Y/N: I suppose she had a more peaceful death than some others.

Koishi: How is being devoured alive a peaceful end?

Y/N: Better than having your entire skeleton broken into pieces that slowly destroy your organs while you're still conscious.

The duo stopped at the beginning of the path leading up to the summit. They both glanced at each other, the man took the first step towards his destination afterwards. The action caused the youkai to become a little confused once more.

Koishi: What are you doing?

Y/N: Hm?

He turned back to face the one asking the question and gave her a confused gaze in return as well.

Y/N: Making my way to the top.

Koishi: Wouldn't it be quicker if I fly us up there?

Y/N: *Chuckle* No way, I'm not letting you carry me even a single meter above the ground. You just gonna drop me down and kill me.

Koishi: Still distrustful...

Y/N: Plus, if you suddenly get attacked, we're both guaranteed to die, especially if everyone here is as strong as that guest that I will be facing soon.

He quickly gave her a quick movement with her hand, telling her to come closer. She did so and he placed his hand on her shoulder.

Y/N: You said you wanted to help, I'll gladly believe you if what you said is the truth.

Koishi: ...

Her smile returned and was even wider than when they left the library. She nodded her head quickly and ran past him, leading the way before turning around to face him with a playful face.

Koishi: You should hurry mister Y/N or else I'm gonna leave you behind!

Y/N: ...Heh, I may be lacking my usual energy but I can gladly keep up with you.

He responded to her challenge by jumping in place, landing on his right foot only and took that small window of opportunity to boost himself past the girl, wind following behind. Koishi's head turned around with an astonishment that changed into a cheerful expression, accepting his request. That was how the both of them began their ascension to the shrine that could possibly heal the curse on the man.