INITIAL NOTE:
I'm a fool. I realised something halfway through writing this and had to adjust my plans for this story. What I realised was that I missed out on the best friendship Shisui can have in this world- a friendship with Tokoyami.
Friendship with Kaachan is cancelled. Now, Tokoyami is my best friend.
All Might.
Number One Hero. Symbol of Peace. A True Hero.
He's learned multiple things about All Might in the past 24 hours of his appearance here in this world.
How his appearance caused the crime rate to drop. How his debut was of him saving over a hundred people. How he's maintained the rank of Number One for years now. How he smiles during crises to make civilians feel safe and hopeful.
It's awe inspiring. The man who, in his mind, foolishly offered Shisui's fanboy predecessor a unique power without knowing his name, has earned and gained the same amount of respect one should give to a Kage. In fact, if he were a resident of Konoha, there's no doubt that All Might would be a favorite choice for the next Hokage once the Sandaime retires.
After being offered One for All, and introducing himself as Uchiha Shisui, the Uchiha heavily argued against making an immediate decision. While he couldn't talk about his recent appearance in this world and 'possessing' the body of a brave teen who truly deserved this unique Quirk, all he needed to do was point out All Might's lack of knowledge about him and his impulsive decision of picking a successor after three quick meetings (one of which shouldn't count) before they came into an agreement.
All Might would train him for 10 months to prepare his body for One for All (wasn't that a surprise? learning about how the Quirk could explode his limbs) and in those months, the hero would observe whether or not he'd be worthy as his successor.
Shisui, in the meanwhile, would be spending every free moment he has into researching about this world, finding ways to gain the kid's memories, creating a stable source of income and food, and filling in topics missing from All Might's teaching (chakra control and capacity, lessening his hand signs, etc.).
The two made plans to meet in 2 days, around sunrise, in a place called Dagobah Municipal Park before leaving. Each focused on their next mission- one, planning a training schedule for his skinny possible successor, and the other, contemplating on where he'd be able to hunt and sleep.
He'd been semi-successful in this venture. Though this world lacks the bountiful greenery he's used to, therefore depriving him of an easily accessible location to comfortably camp and hunt, a shinobi is trained for any and every possible survival situation. He may have only spent a year in the academy due to the Third Shinobi War but his knowledge of 'what to do if stuck in a crowded enemy territory with no supplies' was abundant.
It only took a quick count of the money he had in his pockets and a trip down multiple shady alleyways to gain the resources he needed to get started.
Smokeless shunshin, chakra enhanced strength, and a few minutes of Sharingan.
These three techniques had lessened his reserves to 60%.
The Sharingan didn't have as much of a drain as he initially expected. He'd initially presumed that it would act similar to Kakashi-senpai, requiring large amounts of chakra for his dojutsu to be used in a non-Uchiha body. Instead, it drained the same amount it normally did in his previous body. His misfortune was that the fanboy had a small chakra capacity.
Maybe the scriptures were correct when they talked about how their ancestors gained the spirit of the Sage while the Senju's were given his body. If the Sharingan was connected to his spirit, it would explain the normal drainage and his ability to activate it in this body.
Still.
Right now, the Sharingan uses 4% of his chakra every minute. Meaning he can only use it for 5 minutes before he's down to 40%. At which point, he'll be tapping on his reserves- a percentage of his chakra capacity he withholds for emergency purposes, such as an ambush, protecting his loved ones, and using Kotoamatsukami.
His best plan going forward is to preserve every bit of chakra he has and to stick to D or E-class jutsus if required. He's in a hostile environment with no Konoha or Uchiha compound to fall back to. He needed to secure food and safe shelter for the night, before diving into his problems first thing in the morning.
Staying away from the populated areas of the city and journeying through empty alleyways, Shisui kept his senses alert all the while keeping his walk casual. With his shoulders hunched, head downcast, and hands in the pockets of his pants, he looked like any normal civilian. What really sold his 'vulnerable' state is his current face and stature, a skinny boy with a childish face- it's the perfect bait.
As he entered another dark alleyway, he felt a presence leaking faint bloodlust nearby, assumingly observing him. Keeping his breath steady, he pushed a portion of his chakra away from his skin, letting it envelop the small alleyway.
41%
There! Behind him, by his right side.
While he didn't check every shadow or hidden area when he entered, he's been trained to spot enemies from the corner of his eyes. For him to be able to stay hidden in his place... he must be invisible to the normal eyes. A camouflage quirk?
Listening carefully, he could hear the faint sound of breathing, an inch or so away from a machine attached to a building which was constantly making a rumble.
Clever.
Definitely an experienced human.
Now to see if they're a criminal or something else entirely.
Shisui walked deeper into the alleyway, heading towards the exit. Once he was in the middle, he heard the man moving away from his spot near the walls and towards him. Having been on high alert, the shinobi was prepared to dodge as soon as he heard a wet slick coming towards him. A tube of pink passed by his left, reaching a few feet away until it hit and stuck to a wall.
Quickly turning around, he saw the man... creature... chameleon-headed man's mouth wide open, the pink tube which had passed by him being his tongue.
Adhesive long tongue. Camouflage. Chameleon head.
He could safely assume that his skills were mostly chameleon based, though it'll benefit his survival not to expect it to be the man's only capabilities.
A shinobi who lives on his assumptions, dies of his assumptions.
Rushing the man, his left hand reached out to grab and pull him by the collar of his shirt, causing him to stumble forwards. Taking advantage of this movement, Shisui followed through with an uppercut, allowing his jaw to slam shut and teeth to harshly bite his tongue.
One advantage disabled.
The chameleon criminal attempted to fight back, widely swinging both fists at him. Dodging each attack using the slightest tilt of his head and body, he waits for an opening before punching the man's temple- not enough to knock him unconscious but enough to disorient.
Green eyes immediately bleed red after his last attack.
The reptile man tripped on his own two feet, falling flat on the floor. When their eyes met, the young Uchiha couldn't help but smirk, watching as he fell into his genjutsu.
34%
Good. It's less of a drain than he'd anticipated. Disorienting his enemy probably helped in regard. Now to get his chakra's worth.
"Hand over any yen you have, and tell me what you know about..."
27%
20%
13%
It took a total of 4 minutes to get everything he needed from the man. 4 thousand yen. Information on the locations he wanted to find, including the nearest and cheapest inn the man knows of. And a few more topics he'd forgotten to ask, including a basic summary about quirks, heroes, and public transportation.
6%
Leaving behind an order for him to go to the nearest police station and turn himself in, Shisui deactivated his Sharingan, exhaling heavily soon after.
That's 2 problems solved. He had a total of 11 thousand yen he could spend, the location of a cheap inn and a ramen restaurant, and if he had enough money by tomorrow morning, a store where he could buy a tent, water canister, several filters, and maybe a knife.
As he left the alleyway to make his way to the Inn, the genjutsu user couldn't help but look up, green eyes carefully checking the rooftops.
Huh...
He could have sworn he felt another presence...
Silently cursing his remaining chakra reserves, Shisui started walking faster, moving towards the populated streets and allowing himself to blend in. Whoever had been observing him, if there was one, would soon lose him to the crowds.
Gaining the locations for food and shelter after a simple one-sided battle, the Uchiha had been willing to indulge in a little luxury, renting a night in a cheap inn and buying bowls of ramen.
It had been worth every yen spent.
Those few hours of sleep in a comfortable bed, with a full stomach, were much needed especially when the nightmares came in.
His death (had it only been a few hours since then?) frequented his dreams- the pain in his eyes, both from using Mangekyou and having them plucked out, the poison entering his bloodstream, being hunted down by his fellow Konoha shinobi, his sworn brother Itachi's face as he explained the situation, his fall to the river, the feeling of drowning...
It added to his usual bout of nightmares, multiple imagined scenarios appearing after he learned of the Uchiha clan's planned coup d'etat, where Itachi, Sasuke, and several of his close relatives and friends died due to each other's blades.
The morning after was simple compared to yesterday. Apart from a surprising ache surrounding his whole body and his clothes seemingly shrinking after having hand washed them, there was nothing mind blowingly shocking. No surprise emergence to a different world, no battles, no wild hostage situation, and no weaving around the truth. It was breakfast, checking out of the inn, and buying necessities plus a few notebooks, pens, and loose clothes on sale.
By the time afternoon came around, Shisui was lugging a backpack filled with everything he needed to survive as he entered Musutafu's public library.
It had everything he needed. Maps and travel guides of Musutafu, Shizuoka Prefecture, and Japan. Detailed history of Quirks and Heroes. And enough knowledge about All Might to fool everyone into thinking he's a fanboy. He made sure to spend a few more of his remaining yen to buy a library card for the next time he visited.
What's more is that he gained three things he didn't expect: an idea as to how he can gain brave kid's memories, knowledge about this world's history of shinobi, and a new found friend.
A hiss slipped in between Shisui's lips, the palm of his hands strongly pressing against his eyelids.
His eyes.
They were burning.
It's not as painful or as bloody as overusing Mangekyou Sharingan but it's an ache he's unused to. His eyes felt as dry as Suna's desert, his vision blurry, and the light coming from the windows were worsening his condition. A quick glimpse at his reflection on the window showcased how the corner of his eyes were red (mockingly complimenting his dojutsu) and slowly flowing with tears.
Maybe he shouldn't have spent 13 minutes of his life with an active dojutsu, speed reading and memorizing 6 books from cover to cover.
His plan worked, however.
He now knew enough about All Might to possibly creep the hero out tomorrow and his knowledge about quirks and heroes could keep him in line with the law or skillfully dodge them.
Blindly reaching inside his bag pack to grab a blank notebook and pen, the teen planted them against an empty space in front of him. If he can't continue his studies the quick way, he'll write down everything he needs to memorize and read them later.
With a pen gripped in his hand and a blank Campos notebook in front of him, Shisui opened his red eyes and...
The sound of fighting and an array of bright lights were coming from the computer in front of him, its screen showing All Might's latest fight against a villain. Glancing at the new notebook in front of him, he carefully wrote the words 'Hero Analysis for the Future' in its blank lines, followed by 'No. 13' and two eager underlines just below it.
Again?
Sharingan instantly deactivated, his mind fully focused on the newest memory he's received. He's been in this library for less than an hour but the amount of memories he's received are outstanding.
True, they were mostly useless and all of them were related to All Might but it's a step towards the right direction.
He learned that fanboy is the truest definition of a fanboy. The memories he gained showed him moments of the kid watching multiple All Might videos or learning about certain facts- such as his weight, height, place of work, etc.
What intrigued him is the trigger for those memories. They seemed to only appear after he's read a certain fact or event. Yet this newest memory had a different trigger. All they had in common was All Might and his dojutsu being active at the time.
Focus.
He'll have time to figure this puzzle out. What he didn't have time for is learning what he needed to blend in. Promising to come back to his previous string of thoughts later tonight, he grabbed the next book about 'the Psychological Effects of Quirks' and carefully skimmed through it, writing down the main ideas being explained in the book.
"Hey! Look at this!"
A loud voice shouted out right by his ear, making the young Jounin jump in surprise and face towards the source.
Right in front of him, a few inches away from his face in fact, was a dark creature with glowing yellow eyes staring at the book he'd been reading.
How?
How did he get close?
He may not be on full alert and he's not a sensory ninja, therefore unable to identify individuals, but every shinobi worth their weight can sense someone this close.
"Dark Shadow, enough. It'll be a dark day if your actions cause us to be banned from this library as well."
Is that a-?
Shisui bit his lower lip, trying to control his urge to grin at the person appearing around the corner. There wasn't anything funny about them (of course not!) but his scowl, narrowed eyes, and brooding personality reminded him of most of his family members... plus...
A crow-loving Uchiha meeting an Uchiha-acting crow? Priceless.
"The last one wasn't my fault! YOU were the one who decided to make a nest in one of the shelves!"
"And you were the cause of the other 4..."
He watched amusedly as the crow-looking guy and his shadow companion argued, taking note of their bird-like similarities and their tethered connection. Was this 'Dark Shadow' a quirk? Recalling everything he's learned about Quirks since he entered the library, it's likely that he is. Of course, it could be that 'Dark Shadow' was the crow teen's twin and they've been connected since birth. He's read a case in Vietnam similar to his imagined scenario.
It's during this observation that he glimpsed the books being carried by the teen, something about rituals, Necronomicon, history of deadly plagues, and what got most of his attention- The Shinobi Art of Walking in the Shadows.
Shinobi? They had those here too?
His attention was brought back as the two walked closer to him, Dark Shadow continually pointing at the book he's reading, specifically the part about the personalities of sentient quirks, while the crow teen gave in and took a glimpse.
"If you want..." the Sharingan user started, hand placed on the book before sliding it to the empty desk beside him, "we can exchange books for a while?"
"Which one?" was the man's quick and suspicious response.
"Shadow Walking. I've never read about it before," he flashed a small smile, finger lightly tapping the book's spine.
"An equivalent exchange. Very well."
They quickly changed books. Dark Shadow and his companion willingly sitting by the desk beside him. It took minutes of silence, almost half an hour, before Shisui peeked up from his reading to ask,
"I know your companion's name is Dark Shadow but can I know yours?"
Dark Shadow answered immediately, seemingly bored out of his mind.
"This guy here's Tokoyami Fumikage but you can call him Fumi! I do!"
A fond chuckle left him. This creature, Dark Shadow, definitely reminded him of home. His familiarity with Tokoyami reminded him again of his summons, as well as the Uchiha cat summons. And his little brother attitude made him yearn to see both Itachi and Sasuke again. Eyeing the topic of their conversation, he arched an eyebrow, silently asking which name he'd be willing to be called as.
"Tokoyami will do. Fumi is a nickname I unwillingly hold. And you are?"
"Uchiha Shisui"
Thus started a friendship between Shisui and Dark Shadow, with Tokoyami being dragged in along the way. While he couldn't exchange a phone number, they'd made plans to meet again in the same place, next week before parting as the sun began to set.
Traveling to the closest forested area in Musutafu, named Bogano Forest Park, and finding an empty area far off the beaten track and hidden from the used trails, Shisui set up camp and spent his second night in this world there.
Dagobah Municipal Beach Park, Musutafu. 5 am.
It's been 36 hours, give or take an hour, since he arrived in this world. With no clue of whose body he's possessing, where he was, what to do, Shisui had made do. He had a temporary place of residence, knowledge about this world, and a few visions in his repertoire.
While he didn't gain new information about fanboy's life, apart from the plethora of All Might facts he received yesterday in the library; his left eye stung repeatedly during his sleep, waking him up every few minutes. Scenes of Itachi talking to him were in the forefront of his dreams. Though he can barely read the man's lips due to the speed of his visions, context clues allowed him to fill in the blanks. His brother, in all but blood, talked about their fellow Uchiha's suspecting him for his death and the current situation of the coup.
The clan's getting restless, more and more are accepting the Elders' idea.
Their previous plan was in scrambles. He's 'dead'. And without the other eye, Itachi could only use Kotoamatsukami on one person which would be suspicious. All he could do is figure out the mechanics of this new ability, attempt to send a genjutsu through those visions, and hope that Itachi would find a way to save their clan.
Walking towards the beach, a camping bag dragged behind him, Shisui bit back a curse. He missed the inn. It may have been a waste of money compared to living for free somewhere, but at least it didn't add physical pain to his sleepless night. His body had been aching since he woke up, most likely due to the harsh ground he slept on.
The temptation to find another criminal, grab their money, and spend another night in a cheap inn grew stronger by the second.
With a hand massaging his shoulder blade, the Uchiha continued moving through his destination, green eyes glancing around every few seconds in search of All Might.
Seeing the slouched skeleton-like figure of All Might, he raised his free hand and waved, moving faster towards the 7 foot man.
"All Might!" he greeted with a small grin, "what's the plan?"
His grin slowly faltered as he took in the hero's confused eyes and the blood spilling from his mouth.
"All Might?" Shisui questioned, worry etched on his face, "Are you okay?"
Shaking his head, blonde locks swinging about, the number one hero wiped his mouth and spoke. "You..." he coughed against his hand, "... look different, Young Uchiha." A skinny hand motioned towards him causing the Uchiha to look confused as well.
Reaching inside his pocket, All Might grabbed his phone, took a step back, took a picture of the sight before him, before showing the screen of his phone to the young shinobi.
What Shisui saw was a teen who had a mix of his and the fanboy's features. His coloration was still the same- dark green hair and eyes, pale skin, and a dark shade of freckles. Along with having the same ears, nose, and skinny body. However, his hair was longer, reaching the back of his head and covering the sides of his face. Eyes were a bit narrower with longer eyelashes. Face slimmed down, losing the baby fat it once held. Eyebrows thicker and longer. And... Did he gain a bit of height? Probably.
"Oh..."
It was the only thing he could say as he continued to stare, hands reaching up to poke his own cheeks. When did this happen? And why did he look like his grandfather with this hairstyle?
"Yes. Oh." All Might chuckled softly, waiting a few more seconds before pocketing his phone, "I've said it once and I'll say it again, young man. You continue to surprise me."
"It'll keep a hero like you on constant alert," he cheekily responded, half a mind running through every possibility as to why this could happen.
His spirit merging with fanboy? Activating his reincarnation changed this body's features? His possession getting stronger?
A loud booming laugh echoed through the garbage filled beach, the skinny form of All Might having transformed to its buffer self.
"Right you are, young man! A hero like me has to be in constant alert! Who knows what dangers lurk in the streets?" With a flat hand against his eyebrows, the Symbol of Peace dramatically looked around, causing Shisui to scoff in amusement. "Now then! To be my successor..."
"I'm still thinking about it," the Uchiha prodigy interrupted.
"... my possible successor... you need to clean up this whole beach!" Arms spread out, indicating the mountains of trash occupying the beach.
"I'm picking up trash in order to strengthen my body in order for it to not explode?"
Each word left his lips hesitantly, shivering at the thought of his limbs exploding.
It reminded him of the Eight Gates.
Stories from Kakashi-taichou and Gai-san gave him a passing comprehension on the topic. It gave a great amount of power which could harm, even kill, its user unless they've excessively trained in preparation for it. Opening any of the eight gates is difficult while learning how to use them without a severe backlash is worse.
The extensive, seemingly impossible, training reinforced this comparison.
"You got it! But there's another reason. After some online search, I discovered this beach has been like this for many years."
Shisui scowled after hearing this, mentally comparing clean, nature-loving Konoha to this world.
"Heroes these days are all about showy stuff. Originally, being a hero meant volunteer service, even if it was considered boring. You can't waver from those roots." Pumping his fist, All Might eagerly continued, "You will restore the coastline for this entire section! That is the first step on your path to becoming a hero!"
As the hero continued talking about U.A. and his 10 month training before the school's entrance exam, going so far as to show the shinobi a schedule titled 'Aim to Pass: American Dream plan', Shisui couldn't help himself.
If I can't clean this beach in 6 months, I'll do 250 laps around Musutafu. If I can't do 250 laps, I'll do 1000 push ups. And if I can't do 1000 push ups, I'll wear a green spandex and orange warmers as my hero costume, he jokingly thought, a hand covering his mouth as he snickered softly.
"Sounds a bit extreme but if you're sure about it... 6 months it is!"
...
Did I say it out loud?
"Wait!" the Uchiha panickingly shouted, hand wildly waving in front of him to dissuade his companion. His actions may be un-Uchiha-like but his ancestors would surely agree how now isn't the time for composure. "I was kidding!"
Even as he continued protesting loudly, All Might just laughed and repeated his words, reminding him of the time he's wasting.
...And so began Shisui's months of 'youthful' training.
CONCLUSION NOTE:
Another realization I had as I was writing this is that the entrance exams would be chapters away. Maybe 3-5 chapters away? I have a lot of plans revolving around these 10 months of training, plans which I can't really say right now but it does involve meeting a few more people. Hopefully the difference between canon and this fanfiction would keep you all entertained.
Also please comment on whether you'd like Izuku/Shisui to have One for All. I'm willing to go for either or, and no matter what, we'll still have mentor!/father figure!All Might. If he doesn't get OfA, it'll go to someone that's not Mirio. I know he's the 'next best choice' or the 'most worthy' one to get OfA but I prefer having the quirk in the spotlight, instead of pushed aside and forgotten until Eri's arc.