Chapter 2: A New World

Flash was going to kill the entity. If he ever had a chance.

Out of all the places the God-like could teleport him, it's a hundred feet in the air. In the middle of the night. With only a full moon to provide light.

"Tch," Flash gritted his teeth as he plummeted towards the ground. He was confident he could survive the fall. He had constantly run into walls at speeds that far surpassed terminal velocity. It just sucked when he did.

Below him was a forest that spread as far as the eye could see. It was safe to say he would have a "soft" landing.

The ninja twisted in mid-air and prepared to hit the ground rolling. He wasn't taking any chances.

Then the trees flew by him, and a river came into view.

"Why me?"

The water slammed into him like concrete. But what affected him the most was the sheer cold it brought. It took his breath away, which was not something that is convenient underwater.

Flash's head breached the surface. He let out a gasp and then started floating his way to the riverbank. Once there, he pulled himself out and took a few steps forward.

"Well, the landing could have been executed better, but I'm now here. Wherever here is."

The hero grabbed his cloak and began to twist it to get the water out. He would need to find a new set of clothes. Or at least another layer. It had to be the middle of winter.

He began shivering at high speeds. The friction forced the water to evaporate into steam. Flash wrapped himself in his thin cloak and started running up the riverbank.

What was his mission? To find Tanjiro Kamado and protect him until Muzan was dead. Future said that the ninja would be dropped off at the beginning of Tanjiro's journey. This means Tanjiro will begin learning the secret techniques he was told about.

It will be in his best interest to learn them beside him. That would help him grow as well.

"But perhaps this situation required additional aid. He would need Tanjiro to be as strong as possible if he would grow alongside him." Thought Flash. "So then I will teach him the ways of the ninja and make him the most powerful being of this time. Besides me, of course."

An additional thought went through the ninja's head. Of his last pupil. The man who is probably the reason why he will never have kids. Not like he had any plans of procreating.

Let's hope Tanjiro respects his superior. Unlike a particular bald guy.

There was also Muzan, the first demon. Whatever they were. If he had the chance to kill that creature, it would be best to take it.

Flash first needed to find him. Since this was before the monster invasion, the world was still split into multiple continents. He would have to see which one and pray he knew the language.

The forest finally broke into a grassy field, making the ninja stop to get a good view. The moonlight revealed the river flowing underneath a shack built above it. It appeared to be an older design. A clue to the era?

He slowly started walking towards the wooden building. The smell of rain hit his nostrils. The storm clouds farther up the mountains must have come through before. The grass was too wet for the aroma to be from an incoming storm, and the wind wouldn't indicate a return.

As he approached the shack, Flash noticed the lack of movement. This wasn't surprising since it was the middle of the night, even if it was inhabited.

There was a shifting sound in the grass to his right, away from the river. In preparation, the ninja's senses spiked, so he grabbed his sword hilt. The rustling stopped, then the figure in the grass scattered away.

"Probably just an animal, and if it is not, I'll just kill it." Flash thought. He relaxed and continued towards the shack.

A different smell filled his nostrils. He stopped to try to process it. It was a similar scent. One all too familiar to the hero.

Blood.

In an instant, the ninja appeared on the doorstep. He raised his leg and kicked the door off its hinges. He couldn't see what was inside due to how the moonlight couldn't illuminate the structure from here.

Flash unsheathed his blade, then shifted the weapon to reflect a small amount of light onto the wall. He quickly located a small lantern close to the entrance. A slight glow emanates from the light source. His hand reached forward and twisted the nob on the side.

He turned around to look at the newly lit room. The left eye twitched at the scene.

The wooden floor was stained with blood. Its source was multiple bodies that lay dead in the center of the building. Their bodies, barely covered by the light, cast small shadows behind them.

The largest appeared to be a man. His throat slipped by several parallel cuts. Possibly claws. In his hands, a Type ii Model B firearm. Flash leaned forward and could smell the slightest hint of burnt gunpowder. The weapon used before death.

The following figure he checked was a woman. She laid face down with her head caved in by something sturdy. Dried tears on her face with her skirt pulled up. A strong aroma made Flash's nose twitch. She had been raped while alive, then killed when finished. The attacker was male.

Flash made his way to the last body. A child whose leg had been pinned under a fallen cabinet. The bone in the foot prevents escape. His age must have been no older than seven. The area around his throat had been ripped out. Bitten. As if an animal had been the cause. Last killed. Possibly watched as mother was raped. They had been kept alive until last for some reason.

He had seen many situations like this in his time alive. Too much for one man. Even if he didn't get distracted by the violence of it anymore, there was one thought that did come to his mind.

"Whoever did this needs to die." Flash thought.

The blood around the boy's neck was the freshest. Something had tried to eat the boy but stopped. An animal wouldn't rape a grown woman. It would kill all three of them and THEN feasted.

Only one thing came to mind. What could have caused this phenomenon in this period? He didn't know much about these creatures, but he couldn't think of anything else.

Demon.

They must eat humans and have attacked this family to feast and pleasure themselves. It stopped because someone had interrupted him.

Creak

That someone was Flashy Flash.

With speed no eye could witness, Flash swung his sword and sliced the arms off an attacker behind him with a single swing of his blade. The detached limbs fell to the floor.

"Huh?" The humanlike creature took a few steps back. His nerves, not realizing that he had been attacked. He took a step back, tripped on the woman's body, and stumbled out the door.

Flash followed with his blade drawn, walking towards the demon. His foe shuffled across the dirt to try to escape.

"That s-speed! Are you a Hashira?!"

The ninja didn't even let another moment pass before he slashed the head off the creature. It bounced towards the ground as the body remained frozen.

Flash swung the blade to the side to flick the blood off the weapon. "So you are a demon. Not much of a threat. At least, this one is."

He turned and started walking towards the house.

Then he ducked underneath a flying body.

Flash jumped back. He looked to see that the demon had attacked while it had no head or arms. "What the hell? Immortality?"

The demon grew back his arms and then turned to face the ninja. The severed head laughed. "You're not a Slayer! They would have killed me with that attack."

A dangerous aura then washed over him. The demon looked up to see the figure of Flashy towering over his head.

Behind him, the demon's body crumbled to the ground. Having been split multiple times.

"Give me a minute."

–

Flash kicked the box holding the demon's remains into the lake.

The ninja sighed as muffled screaming came from the container beneath the surface. "That takes care of that. Now what?"

–

Flashy continued to walk down the dirt path, searching for a way to Kamado.

The dirt didn't bother him too much, but he still missed the clean room the association gave him. Oh well.

He continued to walk down the trail. The sun would rise any minute now. It would be in his best interest to get some rest before the following night.

Flash sighed. "Future, you should have dropped me closer to Tanjiro."

The light hit his back and reflected off his white cape. His sword glistened from moonlight to sunlight.

"Morning? I guess time went by faster than I gave it credit for."

Flash then took off in a sprint. Without worrying about demons, he could make it through the forest with little difficulty. And it looked like these demons were afraid of these beings known as Hashira. Perhaps their fear would be enough to keep them off of him. At least for now.

He finally arrived at a small shack in snow-covered woods. The lights were on inside the building, so he assumed those who lived here were wide awake.

When he went to the door, he hovered his hand over it and froze.

Something sharp had been pressed against his back. Only enough to threaten him, not enough to do any damage. Something, or someone, had been skilled enough to avoid making noise to the point that even the ninja had struggled to pinpoint them.

It was embarrassing.

"State your reason for being h…." The man who had snuck behind the hero took his turn to freeze as Flash appeared behind him with a blade to the mystery man's neck.

They stood in silence for a moment. Flash took this chance to look at the man's appearance.

He appeared to be at least sixty. Grey hair covered his head. A red tengu mask blocked the features on his face. His upper torso was covered in a cloud-covered kimono with navy-colored pants.

The older man's feet had black socks with sandals. White kyahan guards could be seen above his ankles.

Flash decided to answer the man's question. Considering he is the guest. The hero lowered his blade. "I am searching for a boy. Goes by the name Tanjiro Kamado."

"Never heard of him." The man continued to look towards his shack. "You have the wrong place."

"You are lying. Do you not think I don't know the tone between an honest answer and deception." Flash put the blade back in its sheath on his belt. "If it changes anything, just know I do not intend to harm the boy."

"Once again, you have the wrong house. I apologize, but the person you are looking for is not here."

It was getting to the point that even the ninja was starting to doubt his instincts. Was this old man telling the truth? Perhaps he arrived too early.

"Why did you threaten me with that sword? Surely you do not do that with every visitor." Flash relaxed his body. Realizing his tense muscles were showing a sign of weakness.

The homeowner finally faced him. "I believed you were someone else. Apologies for that as well."

Something then caught the corner of the hero's eye. His blue eyes shifted to his right, and he looked through a slightly opened window. The older man's hand twitched. He was prepared to grab his weapon.

Inside the building, a girl was tucked into a set of blankets on the ground. Long black hair spread out beneath her head, with the color turning orange toward the end. A stick of bamboo was placed inside her mouth.

The girl wore a light pink kimono and had a black blanket over her. She appeared to be asleep.

"Explain."

Without taking his focus off the girl, Flash raised his left hand and gently redirected the sheath of a sword, which had been swung at his neck with the intent to knock him out, over his head. Then grabbed the old man's wrist and rotated his body until he was facing the house again. Finally, the ninja wrapped his right arm over the elder's neck.

In real-time, it appeared that the blue kimono-wearing man had teleported into a chokehold. Beneath the mask, the elder blinked. Not realizing what just happened.

With the hold not bearing much force, this allowed the captive to talk. "Have I gotten slower, or have the standards for Hashira improved?"

So the old man thought he was there to kill the girl.

"I am not a "Hashira" or whatever that is."

"Prove it. Hand me your sword."

Flash pushed the man forward with his left arm, forcing the man into a slight stumble. He then unsheathed his weapon and flipped it in his palm, so the hilt was facing the opposite direction.

The kimono-wearing man brushed some dust off him and then grabbed the sword. He tilted it and brought it up to his face. Oddly enough, he breathed in heavily, taking in the scent of the blade. After a second, he whispered to himself. "It's not imbued with sunlight?"

"What does sunlight have to do with anything?" The hero asked.

The elder gave the sword back to him. "Come with me inside. I may not trust you, but perhaps an explanation will change that."

–

Flash sat with his legs crossed. His white cloak folded behind him, leaving him in just his ninja gear. Weapons rested in the corner to his front right, which went against his training to keep his tools close.

Across from him, the elder sat in a similar position, facing him. A candle rested between them, casting shadows on the walls as well as making their faces seem more tense.

To the left, the girl silently slept. Completely unaware of the two individuals. How she had not awoken remained a mystery to the hero.

"Let us start with introductions," the old man began. "I am Sakonji Urokodaki, former Water Hashira of the Demon Slayer Corps."

"I am Flashy Flash, a member of the Hero Association. Originally ranked 13th of S-Class, but with so many joining the Neo Heroes, who knows."

Urokodaki glared at him. "I don't know who they are."

"And I don't know what the Demon Slayer Corps is, or a Hashira for that matter. We are on even terms." Flash remarked.

The Hashira huffed. "What sort of name is "Flashy Flash"? "

"The type that belongs to a man who was given a number as a kid."

The elder sighed. "Fine. You explain your story. If it's believable, then I'll explain what the Demon Slayer Corps is."

A blank expression spread across his face, similar to that of Saitama's. "Fuck."

"What, didn't think you'd make it this far?" Urokodaki asked.

Flash leaned his head back and sighed. "No, there is just no physical way you are going to believe my story."

–

"...and that leads us here."

Urokodaki stared at the man so intensely that the hero could feel the eyes of the man on him. He couldn't blame the retired slayer. The story was just too much.

"I don't believe you." The elder stated. "But your story is so incredibly berserk that there is a chance it can be true."

"Well, it's better than nothing. How about I prove it to you?" The ninja replied. "Whatever it takes."

Urokodaki brought his hand to his chin. "Hmm…"

They returned to silence for a short while as the elder thought to himself. Flash became bored and started looking around the room, glancing at the tiny details.

It seemed to take forever for the man to make a decision, but eventually, Urokodaki let go of his chin and stiffened his body. "Bring me the remains of the demon. Or, at the very least, the box."

Flashy Flash nodded, then rose and walked to the door. As he did this, the retired slayer shifted himself to be between the girl and the door.

When said door opened, the sunlight briefly hit the old man but completely missed any of the girl's skin. When the room went dark again, Urokodaki let out a breath he had been holding.

About fifteen seconds later, a knock was heard on the door. The former-hashira quickly grabbed another blanket and dripped it over the girl. Then proceeded to the entrance and opened it.

Outside, the hero stood with steam rising from his ninja suit. Under his right arm, a small wooden box could be seen. A muffled voice could be heard from the demon crammed inside.

"Here is your proof." The ninja tossed the box to Urokodaki and then walked inside to return to his previous spot.

Once the slayer closed the door, he did the same with his position. When both swordsmen were in place, he reached down and unlocked the box.

The first words they heard were, "Kill me! Just fucking kill me!"

The once proud demon had been reduced to a mouth, an eye, an ear, and a bit of brain. The rest of his body was ditched back at the river. He was currently crying out of his remaining eye. Somehow.

Urokodaki continued to look down at the demon. Then gave a stern reply. "No."

He shut the box, then slid it to the side. "Alright, now I believe you."

"What will you do to the demon?" Flash asked.

"I'll bury him alive and save him for later. Now let's get to my end of the bargain." Urokodaki stated.

The ninja relaxed in his spot as the elder began.

"Hundreds of years ago, a man by the name of Muzan Kibutsuji appeared. Or, as we call him nowadays, the first demon. The only demon on record who can create demons." Urokodaki explained.

"On record?"

"There are rumors that some of the higher tier demons could possess enough of Kibutsuji's blood to turn others, but we don't know for sure."

Flash began thinking to himself. "So there are possibly other demons I need to kill aside from Muzan. They shouldn't be a problem, but perhaps something to keep in mind."

Urokodaki continued. "In response to the new threat of demons, a group emerged known as the Demon Slayer Corps. Led by the Ubuyashiki family. They began hunting demons with any method at hand."

The slayer turned to look at his sheathed sword in the corner. "But eventually, a new way to fight demons was created. A mixture of sword techniques and a breathing style that enhances an individual's strength and speed. Those are probably what this "Future" told you about."

This piqued the hero's attention. He could handle the demons with ease. He doubted they would cause him much trouble.

But the Future's warning made him uneasy.

If Past's power went back far enough into Flash's past, then there would be some enemies that could provide significant problems. Platinum Sperm, Garou…

Ninja Leader

He needed to be ready. Whatever the cost.

Even his pride.

Flash slowly stood up. He had heard enough about this time to make a decision, even though he intended to learn more.

The ninja then got on one knee and bowed to the elder. "Sakonji Urokodaki, I humbly ask you to teach me the ways of a slayer so that I may not only vanquish my enemies but the demons as well."

The S-Class hero had never been forced to do this. He had always believed himself superior to the other fighters around him. But recent events have begun to shift his perspective. It was time to make an attempt to change.

The former hashira didn't let a single noise escape his mouth. He didn't want to reveal his surprise at the fact someone stronger than him would so humbly ask the elder to teach him, even if it was a smart move on Flash's part.

"On two conditions," the hashira began. "One: you will not tell anyone your full story. If future events do lead to our victory, then we should try our best to keep them intact. From here on out, you are a ninja from across the country. You are the sole survivor of a village that was destroyed by a demon. You seek revenge against the demons for what they did to you."

"Seems fair enough. What is the second condition?" Flash asked. He raised his head to look the elder in the eye.

"Two, you will teach Kamado the ways of your speed. Do this to increase his chances of survival."

The ninja gave a slight grin. "So he is here?"

"Yes, he is in the woods trying to cut the largest boulder in the forest. Using what I taught him to get stronger." Urokodaki replied. "The sister you were told about, Nezuko Kamado, is right here." He waved his hand in the girl's direction.

It finally clicked for the ninja. "So her condition is…."

"She has been transformed into a demon. Tanjiro vows to find a way to reverse the effects. But if the Corps found out about her, Nezuko and Tanjiro would be forced to commit seppuku."

"Secret is safe with me."

Urokodaki stood up. "I will tell you more tomorrow. For now, you may rest. But be warned, training begins tomorrow."

The ending felt rushed, but you guys waited long enough for a new chapter.

I do apologize. I literally had a seizure and had to get surgery. Rest had to be more important.

Also, I started a prequel to Martial Warrior on AO3 if you want to check it out. Be warned. I may rewrite some chapters to make them longer.

Finally, thank you for your support. It is greatly appreciated.