After Naruto brought Sasuke back from abandoning the village because he didn't treat him with kid gloves they banished him so Naruto with the guidance of Kaguya found his heritage then stole all of his scrolls that he already had and was led to Uzushiogakure with her help he made the island invisible and apear abaonded while he rebuilt it he also found a seal to teleport the island anywhere he wants so all he needs to do is figure out where he wants to go with Kaguya's help Naruto learns sealing justsu to extract biju he also learned how to summon the Gedo Statue also with her help Naruto kills all of Akatsuki and every jinchuriki he also kills Orochimaru by performing the reaper death seal instead of Naruto's soul the Shinigami took Orchimaru's from every curse mark there is so he can't come back as well as every Akatsuki member the one he enjoyed the most was Hidan as he was always cheating death.
The Shinigami gave every ability to Naruto he also gives him a magic network it works exactly like the chakra network except it runs with the magic from Earthland aka Fairy Tail World but Naruto's body goes into shock at such a foreign thing being implanted into his body as well as every tailed beast merging wth Kurama with her becoming the 10 tails as she aborbed the carcass that was the statue after Kaguya was freed Zetsu was also absorbed by Naruto and the Shinigami once the ritual is done Naruto is put asleep until his body can handle the stress of everything it's going througth.
After she exits the room she discovers from the lovers she absorbed that there's a new energy called magic she decides to go to the library to learn all she can about it turns out that it's older than chakra and is older than she is the books and scrolls she has only tells her where she can go to learn magic and the history of it she sees that with her current powers she can only access 1 of the 3 magical realms:
Britannia
DXD
Earthland
She decides to go to Britannia first seeing as it's the weakest of the 3 and is the newest of the 3 also has the best way to learn how magic works she takes a trip there when she gets there she is amazed by the way the realm looks she makes sure to arrive 4,000 years before the great war between the races it takes forever to explore everything eventually she is able to trick people into a room using Eida's power she absorbs every race there is.
She practices every type of magic the realm has then uses it to battle the other races in various skirmishes to get combat experience afterwards she decides to leave then heads to the DXD realm 100,000 years before the great war she travels the various kingdoms and is disgusted to find out that this is where the other gods have gone she decides to use her various powers to punish them and become the top god of the realm like she did in Britannia it takes centuries but she eventually conquers this realm and absorbs every race but regular angels it takes her 25,000 years to conquer everything and master all of her powers it takes another 35,000 years to make them worship her as a god the only people stronger than her are Ophis Big Red & 2 deities from Britannia The devil king and the Goddess queen.
She decides to head home to seduce her chosen mate make him a king and figure out how to use the magic of the third realm from her research it's going to be harder to use than what she has learned so far she could go there but she doesn't want to risk losing her chakra so she decides to run some tests first before going there she takes several different races from both realms takes them back to the Elemental Nations before chakra existed then gives them chakra coils teaches them how to use it properly makes them Chunin level then sends them to Earth land one at a time lets them stay there until they call then brings them back to discover that they lost their chakra at first then they got it back a few months later and they could still use their magic.
All in all she was happy with her experiments she sent them back where they came from after training them back to where they used to be then she heads to Earthland herself when she gets there in between all 4 realms she discovers how she can manipulate it to her will so she uses this to make sure that she will have all of the powers she has obtained in Earthland she even gives herself magic from their realm makes herself the strongest being there is in Earthland she even makes herself a royal due to rule everything she makes Naruto a long lost prince from an extinct and ancient royal family with a horrible past she absorbed every type of magic and race there is then she heads back to Uzushiogakure to grab Naruto stuff she dresses him in Anbu gear gives him several books on every ninja art including the Iga as well as the Taiamin she even gives him material on the League of Shadows then includes a teacher to teach him she magically has that teacher know everything that she put into the scrolls as well as a fox mask that's white with burnt orange swirls then carries his body towards the Earthland portal gives him both chakra and magic undoes the sleep spell tosses him inside then decides to hibernate where no one will find her the moon.
Naruto wakes up groggy not knowing where he is what land he's in or how he got here he discovers that no one he knows is alive or fighting in this age it's guys with armor and swords using some strange energy and tactics like he's never heard of before decides to see where he is while he's walking around this new world he discovers that his chakra control, reserves is back to square one and he has all of his stuff on him surprisingly including his swords but they've changed from the Executioner's Blades he used to have now the blades are curved like a scimitar there's no hole in the blades they're both black with orange foxes spitting fire wind and lightning towards the the blade the cross guard has a fox which looks like its trying to eat the blade the hilt is a curved black handle with orange cloth wrapped around it and the sheath is black with orange foxes he also discovers that his scrolls are full of training materials which is exactly what he wants to do first he needs to find a place where there's no people around so he taps into Kurama's chakra then heads to an island with mountains forests animals and every other type of terrain on Earth best part it's completely in the middle of know where and nobody lives here.
First thing he decides to do is scout the island with some shadow clones it takes a few tries but he's able to make 20 clones he sends them to scout the entire island while he decides to locate a place to live he finds a place in the mountains that suits his purpose he opens the bottom of his sheaths and 2 scrolls falls out one labeled home the other labeled camp he opens the camp one first inside there's wood bricks food scrolls flint cardboard shovels axes rope canteen first aid kit survival guide ninja tools his kunai pouch shuriken holster fuinjutsu equipment trap making stuff his prank equipment and stuff to wash clothes with as well as water buckets.
The home scroll opens it's a 1 story house that's made of stone on the outside inside it has wood floors wood walls 3 bedrooms 2 bathrooms the upstairs is the second bathroom and the bedrooms the basement is his armory other than that there's a dining room kitchen living room and a room that he made larger than the whole house with seals and turned it into a library/ study he also has scrolls for each room first he decides to unpack the kitchen which takes him a couple hours then he does the bedrooms it takes forever because he has to put the bedroom stuff together like the bed frame night stand and the dresser then he uses clones on the rest of the house while he heads to the library to unpack his scrolls he's astounded by the amount of volumes in the scrolls he even didn't remember putting so many things in these scrolls he decides to make the library different then it was back at Uzushiogakure instead of them being in chronological order he's separating them by category and alphabetical they are:
History
Geography
Math
Politics
Seduction
Espionage
Trap making
Survival
Stealth
Medical
Assassination
Interrogation
Torture
Warfare
Strategy
Fuinjutsu
Ninjutsu
Genjutsu
Taijutsu
Kenjutsu
Chakra control
Each subject has books that goes from Academy student - Anbu operative he also sees that there's a Jutsu to summon a teacher at varying stages of training he decides to look at the teacher list:
Iruka Umino - Academy student - Chunin
Kakashi Hatake - Genin - Chunin
Jiraiya - Chunin - Jounin
Anko Mitarashi - Genin - Jounin
Kurenai - Genin - Chunin
Ebisu - Academy student - Chunin
Tobirama Senju - Academy student - Jounin
Upon seeing the teachers at first he was disappointed until he unrolled the scroll more and saw the 2nd Hokage's name as well as how extensive his training is the jutsu says that he can only choose 2 teachers he chooses Iruka and Tobirama before he casts the Jutsu he gets feedback from his clones telling him that other than wild animals and fish there's nothing else here so he heads to the forest builds a school some targets sparring ring unseals a chalk board puts it on the wall makes a podium 30 student desks with seats like back in the Academy he builds a cafeteria , a library with copies of the books he has only they stop at Genin he even made copies of the text books he also builds an obstacle course as well as stuff for camouflage then he goes hunting for fruits vegetables meat and water he finds what he wants by stealing it from the people killing each other he even finds booze cheese and seasoning puts everything in the ice box summons Iruka inside of the classroom and tells him that he wants to learn everything but only until he becomes a Ninja the Iruka clone smiles then begins with the Iga Ninjas.
Naruto is intrigued by the first Ninjas he absorbs everything that his teacher is saying he even takes notes on everything and every subject after that it seems to be dragging on forever but he sticks with it and does the book learning first even though he hates learning this way he can see the benefit in knowing these topics after learning everything up to Anbu level book wise which took him 100 years then Naruto summons Tobirama who begins training him in the various techniques from the Iga Ninjas, Taiamin the League of Shadows and Ninjas from the Elemental Nations after relearning everything and passing the Chunin exams he summons his fox summon.
Tobirama decides that for Naruto's training he needs more than just the regular Jutsu of the regular Shinobi he needs to branch out to the other areas of the Shinobi arts thus he begins teaching him the other ninja arts:
Assassination
Infiltration/ Espionage
Torture/ Interrogation
Medical/poisons
Kenjutsu
Taijutsu
Fuinjutsu
Genjutsu
Ninjutsu
Chakra control/ sage training
Warfare/politics/ survival
Tobirama is a strict teacher who puts Naruto through hell making him wear weights until he's strong enough for seals he even makes him wear a Jounin vest that weighs as much as he does his silverware, cups, plates, clothes, towels and doors are weighted even his swords have had extra weight added to them making them 9 times heavier before Naruto can use his blades his teacher makes him practice with a wooden one and when he's ready a blunt katana that weighs as much as his sword until then he makes shadow clones splits them into groups of 50 to focus on everything else that his master wants to teach him even with the clones help it took him 900 years to complete his training reason being is that he spent the past 300 years mastering his biju powers and 300 on his ninja skills occasionally training with every sensei on the list but one Ebisu.
In his last 300 years of training he spent those on his elemental affinities and his subelements:
Fire
Earth
Lightning
Water
Wind
Subelements:
Ice/snow
Crystal
Lava
Particle
Storm
he also trained in how to be a samurai should he need to he studied every kenjutsu style and on how to read an opponent just by looking at their eyes as well as their body language, posture, muscles, watching their feet and behavioral patterns he also puts a genjutsu over the Island so no one can find it even puts whirlpools around it as well as constant storms to deter those who might seek what he's going to be leaving behind just in case he puts several traps all over the Island only one area is safe where he did his training at.
He makes sure that his traps don't work with the wildlife on the island just against humanity he also takes every book scroll training aids including the academy only thing left is his mountain side house puts them into a giant scroll heads into the mountain makes a bunch of caves and caverns that seems to lead to know where he makes several drop offs dead ends traps that kill on these random paths he makes a secret path in one of the tunnels he makes several twists turns going multiple directions each one feeding back to the other tunnels one leading to a way out each path is more dangerous than the next the hidden path goes down deep inside the mountain he creates a room for the scroll then disguised it as the way out and the path leading to it.
Once everything is up to his standards he decides to leave the Island for the first time in 2,000 years he unseals the boat he came to the island with then begins exploring this new world every island is different some are tropical, arctic, rainforest, desert, and others downright dangerous after that he goes inland to explore the various countries he makes it to several of them before finding out that half of this world is at war the other he decides to stay out of it at first until it arrives on the doorstep of his temporary home destroying his peace and quiet.
After he got tired of exploring he decided to find a place to live for awhile he decided upon the land of Ishgar because it's not apart of this conflict yet he sets up in the country of Sin it's where the criminals, thugs , gangsters, whores, murders, thieves, and mercenaries live so he has a small restaurant and a small cabin he pays them what they want and they leave him alone until today when he saw his restaurant getting demolished and raided by the invaders as well as the criminals he pays.
After that he heads home goes into the woods digs up a chest with a few scrolls one has his pranking equipment along with his trap making stuff the next scroll contains his armor that he made after he completed his training along with his shuriken holster and kunai pouch the final scroll contains his swords along with a strap to attach them to his back he puts everything on including his Anbu mask he waits until the war has engulfed everything.
Then he begins attacking both sides he starts by making them fight each other in certain areas then killing them destroying supply lines ending skirmishes before they begin by wiping out both sides then leaving evidence of the invaders as the culprit which he soon learns after some investigation to be the Alvarez kingdom turns out that they want to conquer the world once he learns that they intend to make slaves of the world he heads over to their country makes clones and does a Fire style rasenshuriken
a Lightning Style rasenshuriken and a wind style rasenshuriken combined he makes each one as big as mount Everest then unleashes the combined attack in the middle of the continent that belongs to the Alvarez kingdom and every other continent but Ishgar destroying 50% of the world's population and countries all with one blast unfortunately his actions did not go unnoticed the magicians though still in their infancy are powerful they decide that someone as powerful as him shouldn't be roaming around so they keep tabs on him.
Aquire his DNA some of his unique energy they captured him put him to work rebuilding the whole world and killing who opposed them when he wouldn't do what they wanted they would beat him torture him burn him and kill those he views as friends it works for several centuries until he breaks free from his bonds he gets his stuff back kills them all and everyone who helped keep him in chains while this was happening before he broke free about 400 years before the magicians made a prison to hold him they used a combination of their magic along with that red energy to make a tomb to seal him away they choose the coldest oldest and most dangerous mountain in the world they made sure that his tomb will never be found.
They also made sure that his sarcophagus would contain him as well as his weapons they do everything in their powers to make sure that no one will disturb this place they even put a spell to increase the snowy weather on the mountain as well as the country below to deter grave robbing and other things the only thing that they didn't account for was a magician being stronger than they were.
After he goes on his killing spree he comes across this snowy country that actually relaxes him despite the almost blizzard he makes his way through the town until he finds an inn gets a room goes to sleep then wakes up to hear chanting his weapons are gone and they put rings on his body to stop him from using his powers then they put the lid on start the ritual which takes them a year to complete as well as put him asleep along with sealing the chamber and his sarcophagus they take no chances they hide it with runes and magic then they go home to live with their families only to die 10 years later.