Tanshu woke up in a dark room, to be entirely honest, it was quite difficult for the boy to even properly identify that he had even woken up since the room was so incredibly dark that he barely saw his own body. The feeling of waking up inside a pitch black room was weird, the boy was obviously confused. How could he have ended up here? What was going on? For a moment Tanshu had settled on the thought that his opponent had crushed his body so hard with his repulsion jutsu that he had destroyed the boy's eyes. Still, weak and lingering reflections of his own body somewhat ruined that theory.
"Is someone here?" the boy murmured under his own nose, then after he braved up a bit once again. Out of nowhere a blue oni mask lit up in the corner, maybe it was just the distinctive color of the mask combined with the fact that the boy's eyes were getting quite used to the darkness that this mask could even be identified. It was the same mask of that man who was with the God-Eyed swordsman, it made Tanshu even more confused as to why he was kept alive. His enemy was not supposed to show him mercy. "What is this? Why am I here? Where are we?" questions spilled like beans from a bucket.
"As far as you need to know... You're still protecting your katei, boy." oni mask replied, it was incredible how the man's dark jumpsuit completely made his entire body disappear in the darkness, only his mask was left visible which would've been quite frightening had Tanshu not seen the man in the gloom of the wasteland. The young swordsman stood up and felt his sword being hung by his side, why would the man leave his sword just hanging? Within an instant, the boy rushed towards the masked man drawing his sword and slashing the mask in two. The mask fell on the floor as it was split in two, eight more lit up taking its place. This had to be an illusion of some sort! Tanshu turned back and grunted angrily. He may have lost against the leader but there was no way in Hell a mere henchman will best him.
"If I were you I'd hear me out, I'm the sole reason you are alive after all..." oni-mask's voice echoed throughout the room again. Tanshu lunged forward cutting all of the masks in pieces with multiple slashes. Right after he did so, dozens of strikes hit him in his back in multiple areas. Tanshu roared in pain as he collapsed onto the soft wooden floor. "As you are right now you are too weak to protect your katei, there are people in this world that are both stronger than God-Eyes and wish your capture. If God-Eyes was to clash with any of the higher ranking Konoha ninja, most of whom still are looking for you because you're a nukenin, he'd die. He may not admit it but that's the reason why he had aligned himself with a still active Kirigakure jounin and two Sunagakure ninja."
Tanshu's sword slashed backwards, the mask collapsed revealing behind it a busted and disfigured face, it was hard to tell this in the dark but its general shape made it look like it had melted off its owner's facial area at some point but instead of falling off it just stuck and kept looking like mashed fruits. "I warn you boy, your next strike will be your last." The voice came right from the fact as its lips moved slightly, the fact that this figure even had lips that could even move was miraculous by itself. The face slowly disappeared into the shadows and the entire room sank into darkness, now there wasn't even a single mask or any clue that anyone was even there. "I asked God-Eyes to leave you alive because you can be helpful to him, despite what that arrogant brat might think, and he may be beneficial to you. What I offer you is power, the only thing that matters, the strength to crush those that threaten your katei and all I ask in return is that you allow us to help you protect it."
Tanshu scratched his head, he had never considered if he wanted another family after the death of his parents. "That being said... I know it's hard, but remember what went through your head at the moment when you were down, I'm no psychic but I've seen that face before, the "my life was useless and I'm about to die and it won't matter for shit" face. Well, with us by your side you can make your life and your death amount to something. With us, you could be a part of a bigger achievement without having to do anything you wouldn't normally do." Tanshu looked somewhere off into the darkness, "OK, even if I'm interested, I'd like to know my new "family" better."
Suddenly a wire tightly constricted around little Tanshu's neck and someone pulled it dropping the boy on the ground. The little nukenin felt his neck bleed, had the man wanted he could've beheaded him like this, this man had more physical strength than Tanshu and despite the boy being just a bratty kid, this was still a feat he had never seen during his days in the wasteland. "Don't get cocky, kid, call us a family and I'll kill you right then and there. I will train you but there will be none of that fucking marshmallow nonsense. I am the Devil and you will be my Demon, in order for a Demon to be born, a man must be broken down and burnt in the flame the Demon comes from. Plus, God-Eyes has problems with his daddy and mommy despite his eyes being entirely the result of who those two were, I wouldn't mention "family" around him anytime soon." Tanshu breathed out and pulled on the newly formed space of the wire getting out of it, the boy then stood up still clenching his neck where the blood was coming from.
"God-Eyes is a renegade, he comes from a faraway place you need not care about built long ago by you don't need to care who. He spits some bullshit about reincarnation or something like that, wouldn't listen too close to what he spouts out of that cocky mouth of his. His goal is to take over the world - all of the villages because his grand...grand...grand... whatever once controlled it. Then, at some point, he just lost it and started talking of himself as God and now having the world is his right as a God... Anyways, he is an idiot and he'll catch his death one day by a ninja that is actually worth his mettle." Tanshu sat down and felt his neck again, he tore off the sleeve of kimono he was wearing and tightly tied it around his neck. It didn't look like any vitals were cut, had it been so he'd have died momentarily.
"He established his "temple" here, calls it the Tower of Bones or whatever because he believes that his grand...grand... whatever once knew how to manipulate her bones or something. He likes symbolism, that God-Eyes... Either way, once he fails and is killed I'll kill his other "apostles" and grant you his eyes, then you will become the true Demon, ironically enough you will be the angel of a God that has fallen, doesn't get any more demonic, don't you think?" the man laughed out somewhere in the darkness. Tanshu stood up and tightened his look trying to see the figure of the man with the oni mask somewhere, spotting his humanoid twisted and slim figure in a faraway corner of the room. "So you are the one secretly calling the shots?" Tanshu asked. A powerful laugh met his question. "No, not really, even if God-Eyes fought me here, where I'm strongest, he'd probably win. I'm just one of the apostles with the weakest link to God-Eyes, you see, unlike Vashia and Hana I am still an active ninja, I am here with the mission from Kirigakure to train an order of young assassins, a brood of demons if you will. That is why I am mostly on your side and if God-Eyes died I wouldn't shed a single tear about it. So, what do you think? Are you ready to let the Red Dog die and be reborn into the Red Demon?"
The rest of the four years, after he had accepted the deal, were difficult for Tanshu to remember clearly. After his small talk with the Oni mask man, who surprisingly didn't go by any names, everyone just referred to him as they pleased, he was introduced to the rest of the apostles. Each of the apostles had a room assigned to them so that in case of attack each of them fought the ninja one on one until one reached the final floor. Each of the rooms was quite compact making a larger brawl impossible, it was simply most efficient to fight each apostle one on one and the groups of ninja that came only came in groups of five at best. As the apostles would've been beaten the attackers would've advanced one floor further until they reached God-Eyes on the final floor. In order to advance a floor the attacker needed to get a key from the apostle inside that floor, they could've tried to use ninjutsu on those bones but, apparently, Hana, one of God-Eyes' apostles, was some sort of sealing prodigy and left protection seals all over them.
Strangely throughout all of the four years of Tanshu's demonic training the tower was only attacked once by Konoha, by a party of Chuunin that were scouting the area looking for Tanshu who was still regarded as a nukenin. The four had found the tower and decided to investigate, they never advanced further first floor where the man with the oni mask lurked. After that day many more bandits came trying to take the tower for themselves but none of them ever even left a scratch on the man with the oni mask. Strangely enough, only the bandits attacked all at once and got in each other's way, from what the man had told Tanshu during training the ninja actually followed his advice to fight him one on one with the rest waiting outside. They still would've needed the key to the other floor anyways.
The apostles themselves were all quite strange people, throughout his four years of training with them Tanshu rarely ever met with God-Eyes again and when he did the man didn't even bother to talk to him or even acknowledge his existence. He was still acting high and mighty and in control when often it was the Demon actually calling the shots and giving the best advice. It was clear that without the support of Kirigakure this man wouldn't have advanced too far with his plot to take over the world. Why would Kirigakure even support such a man was a question to Tanshu and one that Demon never answered to him, it must've been the fact that God-Eyes was targeting Konoha first, after all, Kirigakure had significant influence over God-Eyes through Demon anyways.
The girl called Vashia was a kind and a nice girl, that being said she was always very shut in her own inner world and rarely left her floor. It was said by the Demon that her floor was modeled after a typical dojo, one that her family had and where she was raised as a child which made the boy believe that Vashia actually was longing for her previous life in Sunagakure. The girl had raven dark hair and always wore a sword by her side, actually, that was all that Tanshu even knew about her, whenever he tried to ask her something or talk to her she politely and very directly answered his question leaving him no openings to know anything more. She was really skilled in avoiding all conversation and stroke the boy as a somewhat shy girl. Why such a person was on the group trying to take down all of the ninja villages and take over the world was beyond Tanshu, she acted and looked most like an actually honorable kunoichi out of the entire group.
On the other hand, the girl called Hana was really just as spoiled as God-Eyes was, sure, she never spoke of herself in the third person or called herself a God but she was arrogant and bratty in her own way. Her floor was located right after Demon's but she always tried to get a higher floor for herself since she disliked fighting. From what Tanshu gathered about her she wasn't even that much of a fighter, more of a supportive role that could do anything anyone wanted her to: she was a sensor, she knew how to heal people using ninjutsu and she was a great cook, she was one of the best seal users in Sunagakure according to the Demon. Still, she always enforced her image of the bubble-gum haired diva, she always dressed too pompously for a kunoichi and always ate only candy, popcorn and fries as far as Tanshu could remember. She also always acted most childish out of the group making God-Eyes often quite annoyed by her but he had a sweet spot for her so he more often submitted to her will and gave her the final chip in the bag or the bigger ryo split or that lovely puppy left over by the Inuzuka who had died fighting Demon whenever she threw a fit.
The training that Demon was giving Tanshu was odd, the oni mask man always asked Tanshu to take some pills, from what the boy understood they messed with his mind for the duration of the training. That meant both good and bad things - for one the boy lost his sense of pain which was for the best, oni mask often beat Tanshu down beyond recognition during training, also his fatigue was always absent when Tanshu woke up making the boy ready for more training next day even if his body was pushed to its limits. On the other hand, it made the boy's body and mind function on sort of an auto-pilot mode, also it made him completely forget anything that happened during the training sessions when under influence of the pills. From what oni mask man told him, it was because Demon didn't want Tanshu training people the same way when one day Tanshu becomes the strongest Demon there was. Apparently, despite Tanshu being a nukenin and his apprentice the Demon still treated him as Konoha ninja as opposed to him being from Kirigakure.
God-Eyes found quite the army of bandits and thugs during the four years, just the promise to freely hide in the wasteland and the fact that Konoha could not legally pursue them in there was all that entire bands needed to swear allegiance to One with Eyes of God, apparently Demon called those eyes "Rinnegan", Tanshu liked that name better than "Eyes of God". Also he started referring to God-Eyes as God-Eyes which somewhat irritated the man, he always forced his underling bandits to address him as "One with Eyes of God" instead of the ruder "God-Eyes", even Vashia and Hana did not address him as Demon and Tanshu did but since Tanshu was Demon's little protégé something let the boy get away with it. Still, the young nukenin had to respect the amount of power that God-Eyes had gathered in only four years, he was almost ready to attack Konoha with that amount of bandits as far as Tanshu's perception was concerned but Demon desperately tried to talk God-Eyes out of it.
"Konoha has a bunch of seals on its gates those cheap tricks will shave off a fair amount of those losers. While you might beat them with sheer numbers and these men are thousands of times the killers that the people in the Leaf Village are but... Sannin alone could blow your army away in just five minutes, we need more ninja that are on their level, even if you..." that was the only moment when Tanshu saw God-Eyes lash out and blow Demon away with his repulsion technique. It didn't even seem like the man had a good reason to, he just hated to be reminded that he lacked the ways to deal with the Sannin of Konohagakure and the Hokage if he needed to. It was true, as numerous as his numbers were, God-Eyes still lacked the appropriate ninja of high level to deal with the Sannin. His four apostles according to Demon only could hold the Sannin back and prove a worthy distraction to them. It was then that Tanshu started to develop a technique in secret to his sensei. Demon-sensei taught him many things, he taught him every little thing that a powerful ninja needed to know about how chakra worked and how appropriate techniques worked, he gave Tanshu many tools but he never asked the boy to use those tools. Demon only wanted to shape the boy the way he saw him fit but Tanshu wanted to be his own man.
For a moment, right before the end of those four years of his training, right before Tanshu started feeling like a challenge to any powerful ninja he saw, before he started appreciating this power he had gained and these new people he had met... This life started to feel good. The boy started to actually feel somewhat happy - the feeling that he had thought he'd never feel and he'd forgotten since his parents had died. Still, something was missing, while Tanshu viewed these people as his family they never really shared his belief. Every time Tanshu wanted to talk to any of the apostles they shunned him: Vashia despite obviously hating her own approach turned away and walked to her own floor, Demon-sensei always tried to kill Tanshu when he tried to even address him as Demon-sensei but those times, when the Demon could even do that, had long since passed and Tanshu always survived, Hana always felt like an older sister to Tanshu. The two always fought each other and bickered like two siblings and it appeared that inside only Tanshu really cared for the other where Hana actually may have hated him.
It was that one day that everything changed and Tanshu was finally shaped into the man he had finally become. That time when four shadows appeared in the distance on the top of the crater that God-Eyes built his tower in one that served as a testament of the power inside his eyes but one that did not intimidate the two men and two women on that slope one little bit. For they were the Sannin: Misu of the Vapor, Howoku the Star of Hope, Chestnut Hanasaku and the transcended Sannin of the past generation, the survivor of the great battle that gave birth to this wasteland - Sorano the Raijin's Prophet!