The Multiverse Voyager

Hello everyone, before we start I would like to clarify this story will be posted on both Wattpad and Fanfiction

"Person speaking"

"Person thinking"

"Other Entity speech"

"Other Entity thoughts"

"Attacks"

If you read on sites without Bold, Italic, or Underline available

"Person/Entity speaking"

'Person/Entity thinking'

[{Chapter Start}]

"It's a pity I didn't bring any demon blood with me" I muttered as I placed the fourth UV lamp around my house, making a secure perimeter. From what I know, neither demons nor demon blood arts can survive the sun so this should secure me from any blood arts that have been spying on me, or any that can be used to ambush me.

'Though' I thought looking around the forest 'I doubt they're strong enough to have something like a Demon Blood Art'. I shook my head, reminding myself not to underestimate the trickery of a demon, especially a desperate one.

"A week of holidays, out of which I already spent 3 days and a half" I muttered, putting on my mask. "That leaves me with another half a week, or three and a half months in this world's time where I can visit other worlds without raising suspicion"

I frowned."That's not nearly enough time. Not only will that not give me enough power to freely explain my abilities but it will also not give me enough time to clear out the demons in this world. Traveling to another world is risky right now, it could have a drastically different flow of time compared to my home world."

I take out my bag, containing high-tech support items at least a hundred years more advanced than the technology of this era. "Training in such a dangerous situation is risky, but I'll have to give it my all"

Placing the support item on my chest, it enlarges covering my body. I almost crumpled to the ground from the weight. These are special weighted clothing designed to help me physically condition myself quicker. If I combine the breathing techniques of this world with the unique physique of my world, I should be at least as powerful as a Hashira, like Gyomei or Mitsuri.

Getting up while struggling, I pick up a weighted sword and start swinging. While technology in my world could easily eradicate demons, it won't help me grow stronger. You may call me selfish, allowing the deaths of innocent people just for my personal strength, but I neither have the conscience nor the morals to care about some random person I have never and most probably never will meet in my life.

"Let's do this until night"

—-----------

The moonlight fades through the wisteria trees near my shed. Picking up my Nichrin Katana, some UV flashbangs, and putting on my mask and training suits, I leave the safe borders of the UV lamps and Wisteria trees and sprint deep into the forest.

Under the suit my face was pale, being forced to work an entire day and having to breathe in a certain way that pressured the lungs was extremely taxing on my mental and physical health, but my determination didn't know anything about being healthy.

I often wonder at times like these, when did I become so determined? Back in my previous life, I used to call my mom to pick up the remote lying right next to my feet because I couldn't be bothered to get up, and yet here I am, risking my life and going through intensive training without a hitch.

Maybe it's because I finally found a purpose like I was talking about before, about dying with a sm- no fuck, don't raise a death flag.

I halt and step back instinctively as I stare at the trees in front of me. If one paid attention, one could notice a soft sheen on the barks of the tree. There was a sweet smell in the air. Looking around, I spotted nothing else out of the ordinary.

Gripping the Katana, I swung it at the tree, only for the Katana to bounce with a *ting* as if hitting a solid metal object. The tree in front of me was not mentioned in the map given to my Urokodaki-Sensei.

I can't slice through boulders or metal with my sword yet. Trainee demon slayers were never supposed to be able to do so anyway, Urokodaki-Sensei just didn't want to lose another student so he tried to give Tanjiro an impossible task.

Still, the tree in front of me was the work of some demon, it's best if I keep this mind for now. I then run beyond the metal tree into the forest.

The forest was unusually silent, something normal for this mountain. I jump on a branch as I survey the forest. There was no air, yet the trees were swaying as if facing a thunderstorm. A blood demon art, something I hoped I didn't have to face.

"Is the demon controlling the trees, or is it just a form of wind control?"

I tried to jump off the branch, only to find myself unable to move.

"What?"

I looked down, seeing layers and layers of branches forming on my feet, slowly raising up my legs. I sliced off the branches approaching, but they just regrew. The training suit creaked under pressure as the branches at the base of my feet started to tighten.

"Water Breathing: Eighth form:" I said raising my sword upwards "Waterfall Basin"

Water sprouted out from my sword as my Katana slammed into the branches, completely tearing them apart in splinters. The tree howled as if pained by the cutting of branches, as more branches started coming out of its body.

Quickly leaping out of the tree, I notice as the other trees start sprouting out branches. As soon as I land on the ground, I'm attacked by multiple roots dashing out of the ground, stopping me from gaining a solid foothold.

Thankfully, I didn't need one.

"Water Breathing: Ninth Form: Splashing Water Flow, Turbulent"

I envision water splashing as it collides against the floor, turning into tiny droplets that splash all over the floor. Envisioning myself as water, I jump across the floor, barely stopping for a second, and easily cover the entire ground.

"The demon can't cover the entire mountain there's gotta be a range limit, but where?"

As far as I can see, the trees were wildly sprouting out branches and roots.

"Water Breathing Sixth Form: Whirlpool"

Twisting my sword around I cut all the branches and roots approaching me, halting them for only a moment before they reform and approach me again. Quickly tip-toeing away from the branches I turn around looking for the demon.

"Come on, anything, there's gotta be something here, some clue, some range limit, some demon randomly hiding that I could just spot in the nick of time"

No luck, all I could see was deadly spinning trees, like those Christmas trees in Doctor Who.

"Fuck this, I'm getting out of here"

Turning around I sprinted out of the woods, or at least I tried to, because as soon I turned around the trees in front of me suddenly uprooted themselves out of the ground and started slithering towards me with their roots.

"Weak demons my ass" I stated, ducking under one of the tree's swipes "These demons are going to be tougher to defeat than the Hand Demon"

While dodging the attacks, I silently winced as pain shot throughout my body. The intensive workout, no, the torture I put myself through was constantly taking a toll on my body stopping me from going beyond my bodily limits like how a generic anime character.

It didn't help that my lungs started to ache, I had been forcing them to maintain Total Concentration for the entirety of the day. If I stay here any longer, it would be either my body or my lungs giving up on me.

"Make a path through all this foliage," I said raising my sword above my head "Water Breathing"

The branches tensed as they prepared to face another attack

Only to find me dropping the sword, revealing a small flashbang in my hands.

"Gotcha"

The flashbang in my hands exploded, instantly bathing the surroundings in a huge dose of UV radiation. When I opened my eyes I saw all the branches and roots around me disintegrating, though the trees themselves were unharmed.

"So whatever it is, isn't controlling the trees, but only the roots and the branches? That doesn't make sense"

I noticed some movement in the corner of my eye. Right, the thing controlling the roots is still there and I need to get out of this forest right the fuck now.

*Crack*

Looking down from the sound came from, I see a small crack on the ground. Said crack immediately enlarged as the ground beneath me parted making me fall down into what looked like an endless pit.

Time seemed to slow down as my body slowly started to fall down the newly formed ravine. Looking around I tried to see if I could find anything to help me or anything to hold on to

"Shit, I can't see the bottom" I cursed as I raised my sword "Water Breathing Seventh Form: Drop Ripple thrust"

This move was the fastest move in the Water Breathing where the user unleashes a quick stab. Using this move I stabbed the walls of the ravine, fully embedding my sword within, adn stopping myself from falling further down.

The walls shook under me, and before I could breathe, a loud crack resounded from below. Thick, writhing roots burst out from the bottom of the ravine, twisting and spiraling upwards like a living spiral staircase of death. They reached for me with immense speed, as if guided by some unseen force.

"Fucking Hell" I cursed, immediately jumping on the embedded hilt of my sword just as the roots lunged for my feet. The blade strained under my weight, but it held firm, giving me enough stability to pull a small flashbang from my belt.

"Should've brought more of these for the patrol" I growled, yanking the pin and tossing it down into the mass of roots below. The flashbang exploded, bathing the narrow space in UV radiation. The air filled with an ear-splitting hiss as the roots writhed and disintegrated into ashes.

What was up with demons disintegrating and not just dying like normal humans? No time to wonder about this stuff, the roots below were already re-forming, crawling down like hungry predators to snare me where I stood.

Gripping the hilt of my sword tightly, I launched myself off the embedded blade, twisting in mid-air to snatch it free from the wall. My lungs were screaming in protest; the constant strain of Total Concentration Breathing clawed at my chest, but I could feel my lungs getting stronger from the strain.

"Water Breathing: Seventh Form—Drop Ripple Thrust!"

Repeatedly using the seventh form and stabbing into the wall again and again, I used the technique to propel myself upward. My body acted on instinct, somehow having enough agility to keep on leaping and climbing with every strike that hit the mark.

I could hardly breathe. Every inhale felt like knives scraping against my chest. My legs burned from the effort to keep up, but still, the roots wouldn't let up. They were growing faster now, clawing their way toward me in every direction.

"Just keep moving," I muttered through gritted teeth, slamming the blade into the wall once more. "Don't stop. Don't look back. You've got this."

The roots were relentless, but so was I. My sword kept on stabbing into the wall and anchoring me for another leap. I envisioned water flowing upwards, breaking through obstacles as it surged to the surface. My body had to become that flow, no matter how much it hurt.

Another stab. leap. The walls were endless, the top nowhere in sight. My lungs were burning hotter; my arms felt like lead. For a moment, the thought crept in: What if I just stopped?

"No!" I shouted, slamming the thought into the abyss where it belonged. My determination wasn't about comfort, wasn't about ease—it was about survival. About purpose.

And then I felt it, my mind connecting the dots as if my body moved itself. The water streamed from behind my sword as my body suddenly became lightweight and propelled upwards. I grinned as I raised my blade upwards.

''Water Breathing Twelth Form: Ascendant Torrent"

A new water-breathing technique created by combining the concepts of the seventh form and the 10th form. This propels the user in any direction they want to, even upwards, in a burst of speed something similar to the first form of thunder breathing.

The roots that were about to catch up to me were left behind as I jumped up extremely high in the air, way out of the ravine in a burst of supernatural speed. While up in the air I noticed that the roots and branches approaching me seemed to slow down, meaning the demon was finally getting tired.

"Water Breathing Tenth Form: Constant Flux, Water Breathing Eighth form: Waterfall Basin"

A water dragon materialized beside my blade as I unleashed the second strongest form of Water Breathing along wth waterfall basin, I slammed down on the ground hard shaking the forest, as if an earthquake had occurred, the resulting vibrations completely demolishing the roots near me.

Water Breathing Ninth Form: Splashing Water Flow Turbulent, Water Breathing Breathing Third Form: Flowing Dance, Water Breathing Twelth Form: Ascendant Torrent, the three techniques that completely focus on movement, if I combine these three then I get

"Water Breathing Thirteenth Form: Raging Surge"

This form is the epitome of fluidity and speed. It combines rapid, unpredictable motions with precise, controlled power. The user becomes like a wave continuously flowing and rising just like the rising tides of an ocean capable of evading attacks while relentlessly advancing.

The world around me blurred as if my eyes were unable to keep up with the extreme increase in my speed. I have no idea if I'm going in the right direction, or if I'll bump into a tree but I couldn't care less about it right now.

Eventually, my breath ran out and my body finally gave in as I stopped and crashed into the ground, my body helplessly flailing and skidding across the floor as it landed and jumped back up from the impact multiple times. After a few moments, my body finally stopped as I stared back at the forest.

My eyes were blurry, but I could barely make out the shape of branches rapidly approaching. I tried to move my body, but my muscles wouldn't budge. My body was already broken beyond belief and the adrenaline had been exhausted.

'Is this how I die?' I wonder 'I shouldn't have underestimated the demons and pushed myself past my limits just before coming out to hunt for demons. I didn't even get to do anything yet,. If only…'

My thoughts stopped as I spotted the roots halting a distance before me as if unable to retreat. I looked at the branches wondering if they finally hit their limits as well.

"No" I croaked out, looking athe familiar tree with a metallic sheen "That tree, it has something blocking the branches". I slowly stood back up as relief washed over me for being able to live another day.

Looking back into the forest, the branches were already withdrawing, retreating into the darkness. Whatever controlled them was still out there, watching. Waiting.

I tightened my grip on my Katana. This fight was far from over.

—-------------------

"Was that a lower moon or something?"

Arriving back at my shed I take off my armor and my mask and instantly get hit by the stench of sweat and blood that had marinated on my body for an entire day. Thankfully the armor and mask were auto-cleaning, but I was not.

Taking out a small box, I opened it to reveal five small syringes. Taking one of the syringes out I inject myself with it, bringing relief to the pain in my body. These are medical stims designed to be used by heroes when on a mission without any medical services available.

Flexing my body, I deduced that while my bones were…mostly fine my muscles had received extensive damage. While the stims will help, they aren't video game items that could instantly heal my injuries. I couldn't go back to my home world and ask Recovery Girl for help either, she'd question how I, a Quirkless student, suffered from such injuries.

On another note, it feels weird when you suddenly gain immense thinking power and then suddenly go back to normal thinking power. Looks like I got some form of enlightenment when in a near death experience. Is this why Odin hung himself? Cause damn I might start hanging myself too.

Ugh, I can't think with this smell

Usually in a place swarming with demons, one would have to find a safe spot to have a bath or make some arrangements like putting a tiny amount of water on towels and wiping the body with it to conserve water. Not me though.

I brought a Jacuzzi with me to this world.

Don't ask how it works the, people in MHA can just bullshit technology somehow. Also, why does this exist? Which hero will ever need a fucking portable jacuzzi with them while fighting villains?

That one washing machine hero? Oh shit, that might be a valid support item for him. Was there someone who was born a jacuzzi too?

Wait what the fuck am I thinking? Just have a bath, eat some premium food, and go to sleep. I deserve atleast this much after the shit that happened today.

-------------------------

Water Breathing Thirteenth Form: Raging Surge

A fusion of Splashing Water Flow, Turbulent, Flowing Dance, and Ascendant Torrent, this form is the epitome of fluidity and speed. It combines rapid, unpredictable motions with precise, controlled ascension. The user becomes like a wave, continuously flowing and rising, evading attacks while relentlessly advancing. The user's body twists and turns with every movement, propelled upward by the surge of water as they slice through the air, leaving no opening for their opponent.