Enter: Universe Breathing! (Demon Slayer Reader)

Final Selection

Nobody's POV

"Black Hole!" (y/n) yells, his Nichirin blade turning jet-black. The blade is so dark that it absorbs all light that hits it, much like the real thing.

"W-What kind of breathing form is that?!" The demon says.

"The kind that'll end all the suffering you caused!" (y/n) yells, bringing down the blade onto the demon's neck.

The blade cuts cleanly through the demon's many hair-snakes and her neck. With no blood splattering everywhere, just cutting cleanly through. Almost as if the matter that made up the area he had just struck was... wiped from existence.

The demon dies instantly. As soon as it's decapitated head hits the floor, it disintegrates. 

I... I did it! I defeated a demon! I say to myself.

The man suddenly then rushes back to (y/n).

"Y-You killed it?" He says in disbelief.

"Yeah, the inn's business should return to normal soon." (y/n) says, sheathing their sword.

"Thank you very much!" The man says gratefully. "We're forever in your debt."

The sun starts to rise over the horizon. (y/n) bids farewell to the man and other inn employees and resumes his journey to Fujikasane Mountain.

Later...

(y/n) is running with what little remaining strength he has left.

"I spent 2 hours at that inn, now I'm going to miss Final Selection!" (y/n) says out loud.

(y/n) sharply turns left, towards the mountain and finally sees it up ahead. It's a good mile and a half away, and (y/n) rushes forward.

At Mt. Fujikasane...

Many trainees are at the mountain. Including a boy with a haori with water patterns on it.

"Welcome to Final Selection." Two childish figures say. "We shall explain the rules."

"Final Selection is a course taken by all trainees who wish to become demon slayers." The black-haired child says.

"It is a course where you must survive 7 days on Fujikasane Mountain, using nothing but your sword and intelligence." The white-haired child explains.

"The purple trees you see around you are known as wisteria trees. They are poisonous to demons so they won't come near it." The black-haired child says.

"Speaking of demons, there are demons that have been held captive here on Fujikasane Mountain as well. You will have to fend them off while you are on it." The white-haired child says right after.

"Now let Final Selection start-." Both children say.

"Wait just a moment!" (y/n) interrupts from the staircase, panting heavily.

"Yes? What is it?" The black-haired child says.

They're creepy... (y/n) says in his mind.

"I'm here to take part in Final Selection as well! Am I late?!" (y/n) yells from the staircase.

"You just barely made it." Both children say.

"Thank goodness." (y/n) says, breathing a sigh of relief.

"Now..." Both children say in unison. "Let Final Selection begin!"

(y/n)'s POV 

Day 1

I'm lucky to even participate. I have no training whatsoever, I only know 1 breathing form, and I have little experience with demons. But if there's one thing I do know, it's surviving in the wilderness. Today I'm mostly going to be scavenging for resources. Any edible berries, mushrooms, or nuts will be my main source of food. I'm going to try to avoid fights to conserve energy.

Day 2

I encountered a demon today. It was pretty weak, much weaker than the demon I fought at the inn. I dispatched it with relative ease. I don't have a good feeling that Final Selection will be this easy though.

Day 3

I didn't get much sleep last night, an agonizing scream jolted me awake at around midnight, and I've been on high alert since. I don't have much energy to fight, I'll have to avoid conflict today. My food and water supply is running a bit low too, I'll scavenge with what remaining energy I have left.

Day 4

Nobody's POV

(y/n) is walking through some trees on high alert, their hand on hilt of the Nichirin blade. (y/n) hears flesh being chopped off.

It's a fight between a demon slayer and demon!

But, this demon's presence is different. It's definitely much stronger than the demons (y/n) has encountered.

Without a second thought, (y/n) immediately runs over to the source of the sound. (y/n) stops to hide behind a tree to observe the situation.

(y/n) peers from behind the tree and catches a glimpse of the demon. Chills run down their spine. 

What the hell is that thing? (y/n) thinks.

The demon is huge, at least 12 feet or so. It's entire body is wrapped in hands, including it's neck. A lone demon slayer with a water-like haori is fighting it.

"I've eaten at least 50 humans like you." The demon says while chuckling. "13 of which were Urokodaki's students, you'll be the 14th."

The water-haori blade demon slayer flew into fit of rage. He charges at the demon, but he is sent flying into a tree and is knocked out.

Quick! Now's the time to strike! Protect your fellow demon slayer trainee! (y/n) thinks, unsheathing his sword. 

The demon reaches out one of it's many hands to crush the trainee's skull.

"I wonder how Urokodaki will feel after his 14th student doesn't return." The demon says to itself. "I wish I could see his face."

"Not after this!" (y/n) yells, jumping out from behind the tree, sword raised above his head. "Universe Breathing, 1st form, Black Hole!"

"W-What?" The demon says surprised.

(y/n) brings the sword crashing down on the demon's arm.

A.N - That's it for this chapter. (y/n) has encountered the hand demon and Tanjiro! Let's hope both he and (y/n) make an epic tag-team against the demon.