Early Childhood:

 Denrei was born youngest of five brothers. His elder brothers were from oldest to youngest Itazuma, Mudan, Hidate and Karuzou. From start, the Hideaki had to fight for his parents attention as it was quite divided. Both parents were active Jounin in the regiment of Kusamuragakure, so the eldest brother Itazuma, who was twelve when Denrei was born, often had to look after his younger siblings. Being the youngest, Denrei often felt inferior to his elder brethren, always trying his best at whatever activities he was performing to claim just a bit of spotlight from his prodigy brother Itazuma and his hard working and determined brother Mudan. This was rarely ever succesful. Denrei was a talented young shinobi, but Itazuma was the biggest prodigy the Hideaki had ever seen in their short existance. Even at a young age, people claimed he had the capability of becoming stronger than the clan founder Shirano was during his prime.

Yes, Itazuma was quite the prodigy, and while Denrei was envious of the attention he recieved, he also admired his eldest brother to no end. Which is perhaps why his failing struck Denrei so hard.

It was while the parents were away on a mission that the nukenin attacked. Hired by one of Kusamuragakure's older and more established clans who feared the Hideaki's growing influince, they hired a band of nukenin to eliminate Itazuma, the clan's much hailed prodigy. They snuck into the compound and managed to sneak into the family's home. But as the enemy assailants went to Itazuma's room, Karuido had spotted them while going to the bathroom.

Karuido awoke his brothers, and together they rushed towards Itazuma's room to help their eldest sibling. They opened the door to his room just in time to see the three assassins standing over his bed, one holding a kunai above the sleeping child. It happened to be Hidate who shouted first.

”Nii-saaaaaan!”

Itazuma's eyes shot open. He grabbed the arm that brough the kunai down to him, stopping the blade just inches before it would penetrate his throat. His other hand immediately reached for his own kunai. He shot up and pulled the man towards him, right into his blade. The other two turned around and ran. The exit was blocked, however, by three kids. They succesfully forced their way through, killing Mudan, Hidate and Karuzou just as five year old Denrei came across the corner.

Seeing his brothers killed before his eyes changed something inside Denrei. The two assailants got away, but were hunted and later killed by the same clan that hired them for failing their assignment and to prevent the act from being linked back to them. From that moment, Denrei grew colder and apathetic towards Itazuma.
He never truly forgave him for being the reason his three other brothers died.

Genin

In his Genin team, Denrei was praised for his wise-beyond-his-years attitude about strategy, sacrifice and priorities, but often criticed for his lack of team spirit, cold nature and distant attitude. He was placed in what many considered to be a perfectly balanced Genin team. His teammates were the tall and muscular Fuuton prodigy Gan, the female Genjutsu user Hibari and the female Medical Jounin Yumi. Denrei was quiet and distant, only speaking when he felt something had to be said. He graduated from the Chuunin exams at his second try, at the age of 15. By now he started realizing the benefits of putting up a more friendly act and getting people to like you, though true feelings of friendship where yet unknown to him. Rather, he surpressed them. He didn't want to get hurt again.

Chuunin

It was during this time that he discovered the usefulness of diplomacy. It started during a mission where missing-nin were planning an ambush on the son of a nobleman, and Denrei, due to their similarity in appearance and age, had to pose as said son while Yumi and the other two Genin stuck around to attack the assassins once they showed themselves. These few weeks were very interesting for Denrei as it allowed for him to witness the more diplomatic side of being a shinobi, a side that certainly had its uses. It allowed him to undergo yet another change; he was still the same cold, calculating, logical shinobi on the inside, but he became somewhat good at making people believe he wasn’t. He also developed a fondness for reading, spending many hours in the mansion’s library plowing through books about warfare, psychology or just regular novels.

Life continued much like this for a good few years. Denrei matured. He became wiser, more powerful and more patient. By the time he reached his late teens, he had been molded into an ideal shinobi. One who saw himself and fellow shinobi as mere tools for the sake of peace, and who wouldn’t allow anything, not even his own emotions, to come in between him and his duty. He didn’t allow himself to grow close to anyone anymore. He was only a weapon, after all. And what kind of weapon would let itself be held back by feelings? Sacrificing one´s own ignorance and humanity for the sake of those of thousands of others, that was what being a shinobi meant. By then, he had already been forced to kill his teammate Gan, by then also a Chuunin, when the Taijutsu was close to getting captured by the enemy, an act that lead to the anger of both Hibari and Yumi, but to the praise of the Sakurakage, whom when he was twenty one years old rewarded his iron-hard attitude with a promotion to Special Jounin.

Special Jounin

Denrei was promoted to Special Jounin when he was 19 years old. By then, his brother Itazuma had become the new clan head. It was also when he learned more about the death of his brothers. A mission had him investigate the clan compound of the very clan that had ordered the attack in search of an enemy infiltrator.
While scouting, he found the clan head's office, abandoned. Figuring this might be the first place an infiltrator would head to, Denrei entered. Upon looking around, he found no signs of an infiltrator. What he did realize was how this clan was one of the the Hideaki's biggest political enemies, and seeing as he was alone in the office of the clan leader he figured out he should snoop around in the documents to see if he could find anything that could tarnish the clan's reputation.

After some digging, he was faced with the truth about the three nukenin that snuck into the clan compound. Communication notes in between them and the clan discussing the mission and the payment. At that moment, Denrei's first immediate desire was to rush out of that building and slaughter every clansman he could find on his way, his pain from the loss of his brothers burning harder than ever before. He was already at the door when he realized that not only would this act likely lead to his death, it would also backfire and leave a huge stain on his clan's reputation. So instead, he snuck away the documents to give to the Sakurakage later.

When he returned to the clan compound, he handed the documents to Itazura, his brother and the clan head. Itazuma seemed as shocked as Denrei was, though somewhat more controlled in his anger. He promised to take the documents to the Sakurakage and see that the clan was brought to justice.

He returned dissapointed. Aparently the Sakurakage didn't think this old incident was enough to threaten the village's stability by acting against a powerful and well-established clan.

Something snapped in Denrei at that moment. He calmly returned to his room and locked himself in for several days. Not a sound could be heard from the room during this time. Just as Itazuma began getting really worried, Denrei opened the door and stepped out, cheerful as he had ever been. Something had changed, though. Denrei's usual pragmatism had turned into raw cruelty. He didn't kill because he needed to for the village, he killed because he enjoyed it. It was as if that bit of unsolved injustice had removed some sort of mental cage and let out a monster.

Jounin

Denrei had something wicked planned for the village of Kusamuragakure. The day he was promoted to Jounin, he reported at the Sakurakage's office. After recieving the promotion, he was sent on a dangerous solo mission where he had to infiltrate a ring of nukenin that had stolen a ninjutsu scroll from the village. As he left the village, the Sakurakage returned home only to find his family butchered across his house...

Denrei, in the meantime, DID go to the ring of criminal shinobi. Only he never intended to return to Kusamuragakure..

Missing-nin

After joining the ring of criminals, Denrei's ability and infamily quickly increased. After some time, he grew bored with the ring and massacred the entire group. Nowhere to go, he started to roam the shinobi world, until he came across a group that piqued his curiosity. A group interesting enough to keep him amused, and powerful enough to put a leash on the Black Mantis.

Ouraboros

Spoiler:


”Keh!” 

Even in the face of the fully formed Gobi, an enemy possessing power far beyond that of any normal shinobi, even as the fireballs he had just created were deflected with seemingly zero effort, Ruuji just wouldn’t stop smiling. This was a situation where most people would be fearing for their very lives; there were only a few elite shinobi in the history of the world privileged enough to ever come face to face with a Bijuu and live to tell the tale. Now that the Gobi was bearing all of its five tails, the threat of not being among those privileged few was becoming bigger and bigger. 

To any other person, perhaps even his companions from Hebi, these moments would’ve been ones of fear and despair. Even the bravest shinobi feared death. While a significant part of it sprung from fear of the unknown – no one knew exactly what came after death – there was also the ties one had to the world of the living and the fear of losing them. Sasuke’s goal was revenge; Uchiha Itachi had killed the rest of the Uchiha clan and Sasuke had to make sure he was sent right after them. The concept of dying without satisfying his lust for vengeance would have been a scary thought for him. 

Ruuji was different; like any person he had his fears. Death, however, was not one of them. While the lizardman was able to explain and argument his views well enough for most people to understand, there were few who could truly peek into Ruuji’s psyche and fully comprehend how he looked at life. He wasn’t a madman due to any kind of social handicap or disorder, or even mild emotional instability. It was due to his complete disregard of life itself. 

During the whole time, Ruuji was thoroughly amusing himself. 

Maneuvering out of the way of the two fireballs that had survived the steam and were sent bouncing right back at him, Ruuji began to doubt the use of his henge technique. His original plan, while transforming, had been to lure Han into attacking him by tricking him into thinking he was Ubume. Only when he was too close to Ruuji to be able to dodge the attack would he drop the façade and treat Han to one of his most powerful ninjutsu; an intense beam of orange fire possessing enough heat to melt through rock and massive steel. While he had other techniques that were more useful and deadly, therefore deserving of an equal or even higher rank, this technique was his number one in terms of pure destructive power and energy. Even if Han, back then in two-tailed mode, would’ve charged at him head-on and powered by steam, charging straight into the beam would’ve still forced him back.

The problem was that at that point in the fight, Ruuji wasn’t expecting the Gobi to come out that quickly. 

The situation had changed now. He needed to put all of his effort and chakra into attacking. Unleashing the Henge no Jutsu, Ruuji watched in his own shape how Sasuke charged at the Gobi. The avenger’s words indicated that something big was coming, and knowing the Uchiha, the Madman of the Hidden Mist was expecting quite a show. 

He was not disappointed. Sasuke’s well-coordinated attack was a spectacle to behold. Considering the power the Bijuu’s blows contained, having the surrounding snakes act as not only a distraction but also to cushion blows and quickly bounce back was quite ingenious. It was always a pleasure to see Sasuke go at it. Even more interesting; the attack actually seemed effective for now. The Uchiha’s blades, one made of metal coated in lightning and one made of lightning itself, managed to inflict several slashes to the beast’s legs and stomach, bouncing in between the snakes quite similar to how Yuki members tended to bounce from one mirror to another when using their renown and feared Demon Mirror technique. 

”Oh, now you’re just showing off..”, Ruuji mumbled as the Uchiha dug both his blades into the back of the Gobi’ neck, the resulting effect resembling a tamer trying to tame an overly large bull. That being said, Sasuke’s moment of victory didn’t last long. The Gobi was quick to throw him off, and in the process of his fall, the avenger was caught by a large hoof. 

This is where his snakes proved their value once again, one of the beasts catching the Uchiha with its mouth. The force of the blow was such that even the massive snake was blown back. 

”Was that everything?” For an instance it seemed like the setup for Sasuke’s big attack had failed. ”This is taking too long.. he can’t keep all the fun to himself forever..”, he thought as he slid his right foot backwards and went into a slight hunch, positioning himself for a fast sprint to rejoin the fray.

That was when the snake shot forward again, spitting out a winged, black figure. It was unmistakably the work of the Curse Seal, a hidden trump card Sasuke only used in the face of truly powerful opponents. It wasn’t often that Hebi came across an opponent powerful enough for Sasuke to use it, but the Gobi more than qualified. It was then, during Sasuke’s ascend, that he noticed something in his hand. A normal chidori at first, but soon it’s color changed, the power of the Curse Seal having increased its power as it had with Sasuke’s body.

”He still had an ability like this hidden?”, Ruuji thought. His mouth opened up into a toothed grin. Those who knew Ruuji knew that it indicated a certain kind of sadistic glee, one of the things that could cause this kind of pleasure being powerful techniques and the destruction they brought. 

As the avenger made his descent, the Gobi had managed to finally break free from the snake’s constrictions and opened its mouth to form what Ruuji assumed as one of the most powerful attacks in a Bijuu’s arsenal. It mattered little; Sasuke was too close and managed to thrust the pitch-black mass of lightning right into the beasts mouth. Ruuji braced himself for the shockwave that was sure to come. 

And it did. The explosion that followed was enough to almost blow Ruuji off his feet; it even required the lizardman using chakra to suction himself to the ground similar to how shinobi scaled walls. The noise echoed through the mountains as the shockwave of the blast resonated in Ruuji’s ribcage, sending tingles through his spine. Joy as a result of the overwhelming beauty of the attack escaped him in the form of laughter, though the echo of the blast made it almost impossible to hear. There was a lot of beauty hidden in such an attack; the sound and visual effects were impressive, but what truly made Ruuji appreciate it to such an extend was its most obvious quality; deadliness. There was a strange, poetic kind of beauty found in the fact that attacks like these were capable of ending lives so easily. People were complex beings; each with different things tying them to the world. Friends, family, bonds of love or hatred. Dreams, ideals, thoughts, emotions and experience. People were complex creatures with the formerly mentioned things all being components to their psyche, yet something as simple as a huge amount of lightning chakra, empowered by Orochimaru’s dark chakra, and someone to wield it on even the slightest whim could erase all of it in the blink of an eye. It was a poetic, ironic kind of beauty that took a madman to appreciate.

That’s when he noticed something flying through the air. It was Sasuke, no longer in his winged form. His body was ragged and in tatters, no doubt having suffered a fair amount of damage from his own attack. If the user of the attack suffered that kind of damage, how about the opponent?

Any human opponent would be quite dead. This wasn’t the case with a Bijuu, though. As anticlimactic as it was, the Gobi was still standing. The attack seemed to have dazed it, allowing for a margin of time to set up new attacks without the risk of meeting the business end of one of the beasts’s hooves or perhaps another Beast Ball, but it was still standing and probably very pissed off.

”So much for that! Looks like it’s up to us now!”, Ubume would’ve heard as she saw Ruuji phasing next to her, still smiling. Biting his thumb, he crouched and slammed the rocky ground as a circular pattern of marks appeared beneath him. Behind Ruuji and Ubume, a frilled lizard the size of a truck appeared. Toho had often been described as large, but right now she was easily dwarfed by the Gobi, which it regarded with an angry hiss. To Ruuji, the malign chakra radiating from the beast only served to set the perfect tone for the fight. To Toho, it was an indication that the white beast was a very serious threat, and her survival instincts dictated fear. Extending its frill, it hissed again before Ruuji gave it an order. 

”Toho, take Ubume in your mouth and hide underground. Resurface and release her when she tells you she’s ready. Do not eat her.”

For once the lizard obeyed without question, and after catching the former OWLS member in her mouth, she quickly sank beneath the surface.

With Sasuke severely wounded and Ubume hiding (though some of her clones remained on the battlefield), it fell to Ruuji to distract the beast now. By the time Toho’s shape had fully vanished, the multi-limbed psycho was already halfway the battlefield, forming hand seals as he went. His current destination was not the Gobi, however, Not yet. It was a large chunk of earth jutting out of the torn-up ground that was positioned perfectly in between Ruuji and the Gobi. At his current pace, the clump would only obscure the Gobi’s vision of him for half a second. But it was enough. 

During that short moment, the seals were finished. 

When Ruuji reentered the beast’s vision, she would see two lizardmen charging at her at exactly the same pace. Logic would quickly conclude that one of them was a clone, and the former Jounin had used the brief margin of time to obscure which one of them was real and which one fake. The truth was different; both of them were clones.

Behind the rock, Ruuji had halted and performed a second jutsu causing him to sink into the earth. Swimming through the rocky ground not unlike water, the former Kiri-nin launched himself upward from the earth again directly behind the Gobi, where its large tails would have prevented the beast from seeing him. This happened at the same time the two clones would’ve jumped towards the Gobi. Several things would’ve happened then. 

The clones themselves both jumped. Initially it would seem that both of them were heading directly towards her face, but then something unexpected would happen. The clone that had gained the most height descended again for the briefest of moments before its feet touched the shoulders of the lower clone. Immediately bouncing off his newfound foothold, the clone would receive a second boost in height and distance itself from the clone. It ascended until it had the sun directly in its back. The light was not as bright as Ruuji had hoped due to it still being morning, but nonetheless it would’ve made spotting the clone much more difficult. While the lower clone sought to slash the Gobi’s chin, the higher clone than descended upon the Gobi like a missile seeking to crash into its nose. 

That was a mere diversion.

A lot had happened in the margin of only a few seconds. After Sasuke’s attack had proven ineffective, Ruuji had been quick to act and summon Toho, succeeding in bringing her into the fray while the Bijuu would’ve still been dazed. The charge (later taken over by the clones) also took only a few seconds, but it was enough for the Gobi to regain her senses and prepare a counterattack. The purpose of the clones was merely to soak up that attack, as well as occupy the beast’s attention enough for the real Ruuji to rocket out of the ground, bounce against a large pillar of rock, and position himself above her. As he began descending, a string of seals was made.

As both clones would’ve collided the Gobi's face, assuming they hadn’t been destroyed by a counterattack yet, she would feel a light weight landing on top of her head. To a creature of her size, Ruuji would feel like a small rodent crawling on top of her. Within a second of the initial feeling, however, a second thing would’ve been felt; a searing pain on top of her head.

”Katon: Tatsu Soku!” (Fire Release: Dragon Breath)

Ruuji’s four hands were positioned like a flower, their fingers pointing outward like petals. From within them, a bright, orange beam of intense flame would’ve plummeted right into the Gobi’s skull. The attack spread an orange glow across the nearby area as an amount of heat second only to magma was sent into the Gobi’s head from point-blank range. This was the attack he was saving for the two-tailed version of Han. Normally a technique used to kill, it wasn’t as big as the Black Chidori, but it was sure going to hurt!