Isshiki Ōtsutsuki

is a member of the Ōtsutsuki clan's main family and the leader of Kara.

Background
Over 1,000 years ago, Isshiki came to Earth alongside Kaguya with the objective to plant a Tree to harvest its Chakra Fruit. While Kaguya, being lower-ranked, was planned to be sacrificed to create the Chakra Fruit, she instead turned on Isshiki, leaving him on the verge of death after destroying Isshiki's lower half. Encountering Jigen and not having the strength to implant a Kāma on him, Isshiki devised a desperate plan and shrunk himself to enter the monk's ear in order to survive his injury by absorbing Jigen's nutrients. Through time, Isshiki came to control Jigen's entire body and embed a Kāma onto his host. Passing on reviving himself through Jigen as his body would probably die within a few days as it wouldn't be able to bear his chakra, he instead opted to cultivate Jigen's body as much into an Ōtsutsuki as possible to be fed to the Ten-Tails for its growth. At the same time, began preparing for a new host.

Upon the formation of Kara, Isshiki through Jigen became its leader, and the Inners collectively agreed on obtaining the Chakra fruit by cultivating a new God Tree huge enough to devour all life on Earth. Eventually, Isshiki found and purchased Kawaki from his abusive father with a large sum of money, to use as a potential new vessel. After taking custody of the boy, Isshiki introduced Jigen as his new father and reassured him. With the assistance of Amado, who at some point modified Isshiki's vessel with Scientific Ninja Tools, the two attempted to transfer Kāma to Kawaki and fourteen other boys in an experiment, with Kawaki being the only known success and survivor. Despite promising him safety, Isshiki put Kawaki through gruelling training to master the Kāma and would constantly berate him as only having value as a vessel, striking the boy whenever he questioned him.

With Kaguya's betrayal and eventual sealing leaving Isshiki alone, he was left with no other option but to use himself via Jigen as the sacrifice for the Ten-Tails, in order to make it bloom into a God Tree. With this intent, he prepared Kawaki to serve as his vessel for revival once he feeds Jigen and himself to the beast.

Personality
Isshiki is arrogant, pragmatic, and remorseless. Common with the rest of his clan, Isshiki cares not for other lives, desiring only to live at any costs and further his own goals with no concern on how many innocent people must die for it, having crushed Jigen's mind and completely taken over his brain and body. Even as he overwhelming Jigen's body with his overwhelming power, he mocked Jigen's tears of pain, declaring him a worthless and defective vessel. In battle, he outright mocks enemies, repeatedly insulting his foes upon overpowering them and relishes in their awe and/or fear of his power. He also shows an authoritarian nature, fully capable of commanding respect among the group, to the point even prideful Victor and hot-tempered Delta are easily silenced by him. He is also shown to be rather vain, storing various trinkets in his pocket dimension, including clothing and glasses of wine.

He is very confident in his abilities, bordering on arrogance. When facing Naruto and Sasuke, the well-considered two strongest shinobi in history, he was completely unfazed by this. At the same time, this self-confidence doesn't prevent Isshiki from praising his opponents and also remaining calm when cornered even actually thanking them for revealing the weakness of his abilities. Likewise, he is willing to admit when he's outwitted, openly declaring Amado's victory in forcing his resurrection in Jigen's body. He is also shown to be a perfectionist, expressing disgust to see his adopted son's preference of his prosthetic right arm over and desire to quickly restore his right arm.

Despite his amoral nature, Isshiki is shown to be able to remain calm even when faced with insult. Generally, Isshiki is formal and courteous, addressing the fellow members of his organisation politely, even extending manners to his enemies, as apologised for not removing his shoes when entering the Uzumaki household. He prefers to only incapacitate enemies when not needing to kill them and even willing to avoid conflict if potential adversaries are agreeable to his terms. He seems to have a sense of comradery, referring to the other Inners as comrades and offering to tell Koji's last words to Amado as a favour to his former comrades. He is very composed and systematic in his approach to matters at hand. Even when dealing with momentary failure, he remains determined as ever, convinced that all will fall into place as he designed it. At the same time, he has shown an irritable side, as when tasks fail to reach his expectations, he can lash out, as he kicked a broken tank after another setback to his plans.

He views those who value peace as the utmost priority as being cowardly and foolish. Arrogant as he appears, Isshiki is very cautious and secretive, capable of keeping the full scope of his abilities secret even from his allies. Very perceptive and deceptive, he was fully aware of Koji Kashin and Amado's treason, yet still hid it perfectly from all. He effectively fooling all the Inners so well that he ultimately tricked Koji and Amado to reveal their true intentions of killing him.

Isshiki is so driven in his goals that he can get over-excited and reckless from the idea of things proceeding so swiftly: Delta noted that money Isshiki had invested for his experiments was enough to buy an entire country. His immense devotion to his goal leaves him to have little to no interest in other matters, willing to leave his defeated foes alive if he deems it taking up too much of his time. Isshiki's devotion in cultivating the Chakra Fruit is such even while alone after losing Kaguya, he was willing to feed his own damaged body via his inadequate vessel to the Ten-Tails, even if this would result in the fruit's inferior quality. Even more, the fact that he would wait for over a millennium shows remarkable tenacity and patience on his part. At the same time, he will do whatever he deems necessary to speed up progress in his plans. After learning of Boruto bearing a Kāma and uniquely having a naturally perfect compatibility with it, he became determined to capture Boruto as a new sacrifice for the God Tree and refused to kill boy, or let him die at all costs for to produce the highest calibre of Chakra Fruit.

Isshiki seems to believe that all living beings have their fates predestined by their genetics, as he stated that Koji, a clone of Jiraiya, is destined to die just like his template due to having inherited his genes.

Appearance
Isshiki bore the telltale features of the Ōtsutsuki clan, including pale skin, and a long, curving horn which grew from his left brow and wrapped around the back of his skull before jutting outward from his right temple, resembling a crown. The iris and pupil of his right eye is yellow with a black wheel-like pattern with eight spokes coming out of the centre, while his left eye was a Byakugan. He bore matching tattoos on his chest and back: on his chest was a vertical column of six magatama topped with an emblem resembling a black mallet across his chest, and on his back was a vertical column of six smaller black mallet emblems. His hair, right eyebrow, and goatee were pale blue trimmed short with unusual alternating zigzag patterns resembling the hair parts worn by other members of his clan, while his nails were painted black.

Isshiki prefered to dress in an elegant, slim cut, white long-sleeved tailcoat with maroon lining and cuffs and an oversized collar that folded back upon itself, over a pair of baggy black pants that often covered his bare feet. The coat was embroidered with patterns matching his tattoos, with vertical columns comprised of eight magatama designs on the sleeves, and a similar pattern on the back, with the second magatama replaced with the black mallet emblem.

Abilities
Isshiki's power is so vast that Jigen's body, despite the various enhancements he gained to be monstrously powerful in his own right, has difficulty containing it, preventing him from using the full extent of it for long. While limiting himself, he could pressure both Naruto Uzumaki and Sasuke Uchiha, the two strongest shinobi in history simultaneously, and upon exerting himself more, decisively defeat both of them, sealing the former while nearly killing the latter. Amado described Isshiki's power as being so immense that if he were to be able to fully harness his true powers, he could destroy Earth with no one able to stop him.

Physical and Chakra Prowess
Isshiki is a very resilient man, able to survive being bisected long enough to find a new host. While possessing Jigen, Isshiki displayed incredible prowess unarmed combat. Even without having Jigen's body access more of his power, he shows tremendous speed and strength, easily kicking Naruto away, impressing the Hokage with his reaction, and effortlessly catching a punch from Kawaki when he had Kāma activated, causing Kawaki visible pain by merely lightly twisting his arm. He is also highly durable, suffering no injuries from a direct kick from Naruto in his Six Paths Sage Mode. Even while severely weakened from his battle with Naruto and Sasuke, he remained fully capable of matching Koji Kashin in hand-to-hand combat. Isshiki has also displayed remarkable proficiency with a large black rod to easily parry blows from Sasuke's masterful skill in kenjutsu. Isshiki also has considerable senses, as he was easily able to sense the presence of Koji's toad that went unnoticed even to Naruto. In his true form, Isshiki's strength and speed are at such levels that he was able to completely outmatch Naruto in his Six Paths Sage Mode, kicking him through buildings without the Hokage being able to react.

Isshiki wields tremendously powerful chakra, compared to Naruto in his Six Paths Sage Mode form by Kawaki. Its sheer reserves and strength at full power is capable of overwhelming Jigen's body with the sheer intensity of it. Even while limiting himself, his sinister chakra was already strong enough to terrify Ino Yamanaka to the point of near-collapse. When unleashing more of his power through Jigen's Kāma, his chakra was such that it intimidated Sasuke into fleeing and later on unnerved both him and Naruto. As noted by Amado and Isshiki himself, his chakra is so massive that it requires a proper vessel to withstand it, as if he were to be reborn in Jigen's body, the man's body would die within a few days — Isshiki believes three days would be the limit.

Ninjutsu
He can use chakra absorption powerful enough to absorb Sasuke's Amaterasu, and levitation. Utilising Yin Release, he can communicate with others using genjutsu. He shows adept bojutsu prowess, able to easily counter the masterful swordsmanship of Sasuke. Isshiki's rods are also capable of draining chakra from the victim, which he can perform with the most minute of hand gestures. He can use Space–Time Ninjutsu, able to access what appears to be his personal dimension, a world with rolling purple storm clouds and desiccated white land. The crater-shaped battlefield is also a gigantic sealing coffin, with its lid suspended above the clouds. He can also use the lid to perform a power Fūinjutsu, able to seal away even the likes of Naruto inside. Only Isshiki himself is capable of breaking the seal and cracking it will only destroy whatever is inside.

Kāma
As an Ōtsutsuki, Isshiki impart a Kāma onto individuals. This seal, being a compressed backup file of Isshiki's biological data, grants the host his powers and techniques, including a huge boost in physical and chakra levels, as well as to absorb chakra. While using vessel with its enhanced Kāma, Isshiki displays such a tremendous level of physical strength and speed that he was able to effortlessly dodge Sasuke's Complete Body Susanoo and Naruto's Tailed Beast Mode attacks and plunge them out with a single attack as well as pummel them severely with just a few punches and kicks. He is also resilient enough to be completely unfazed by being burned by Amaterasu, which could harm even Tailed Beasts, proceeding to calmly absorb it. He can also connect between two targets bearing his mark to instantly teleport to the other target.

The true purpose of Kāma is for Isshiki's genetic information to overwrite that of the host, allowing him to transcend death and be reborn at the expense of the vessel's individuality. Isshiki applied the Kāma onto Jigen after nearly dying against Kaguya's attack, but knowing Jigen's body would die days later resurrecting through him, Isshiki used the Kāma instead to better control Jigen's body as a vessel. Nevertheless, Jigen's would endure great damage if accessing too much of Isshiki's power for prolonged periods of time.

Through scientific aid, Isshiki was able to transfer his Kāma to a more suitable vessel, albeit with a very low success rate, with Kawaki alone out of fifteen children to have survived the process. At the same time, Isshiki would still have to mature Kawaki's through arduous training to ensure he could resurrect in his body. Isshiki is also able to synchronise the Kāma he placed onto Jigen with that on Kawaki to open rifts in space between the two vessels.

As with any Kāma, Isshiki had no control over its progress once it is applied. Hence, when he and Jigen were burned to death by Koji, Isshiki was forced to reincarnate into an incomplete state using Jigen's charred corpse. At the moment of reincarnation, every other Kāma that Isshiki placed vanished, thus preventing Isshiki from stockpiling on backup vessels for further reincarnation, leaving him vulnerable to a permanent death unless he could apply another Kāma.

Dōjutsu
As an Ōtsutsuki, Isshiki possesses a Byakugan, but apparently only in his left eye and cannot access it when in a vessel. It grants him the usual near-360° field of x-ray vision (with the presumed exception of a small blind spot at the upper thoracic vertebrae) and the ability to see the chakra pathway system, though there are special barriers that he could not see through, such as an underground facility within Konoha that was made with such arrangements. Uniquely, his Byakugan doesn't appear to make the veins by it bulge when activated.

With his unique right eye, Isshiki is able to perform Sukunahikona, a technique that allows him to instantly shrink himself or anything non-living target he sees and just as quickly restore its original size. After shrinking a target, he can use Daikokuten, which lets him store any of his shrunken targets into a pocket dimension, which he can summon and at full size at any given time. He tends to make regular usage of this, manifesting replacements of destroyed furnishings and other items, like a table, food and drink, and even lit candles. He could also use this combination in combat to great effect, by shrinking weapons and objects and then summoning them to full size right onto his opponents, causing severe damage by surprise, or by reducing the size of elemental attacks and projectile weapons to prevent them from harming him. His most common tactic with it is to instantly summon large black rods to impale his foes. He can also reduce the size of buildings to cause severe collateral damage and remove stable footing from his enemies. He can also manifest massive black cubes which he can freely manipulate. These black cubes disrupt sensory abilities.

Kara Actuation Arc
In the anime, Isshiki called a meeting with the Inners, informing them of the destruction of one their facilities in Amegakure set by an Outer.

Ao Arc
Upon an aircraft carrying Kawaki crash landing, Isshiki held a meeting with the other Inners of Kara to discuss the urgent situation, during which Koji was given the task of recovering Kawaki. As he dispelled the genjutsu, Isshiki voiced that their group must recover the vessel at all costs.

Kawaki Arc
While eating a meal with Delta, she voiced her frustrations about the time it was taking to recover Kawaki, during which Isshiki gave her permission to partake in the recovery of the vessel with the condition that she follow Koji's ways. Later, after Delta's decisive defeat by the Seventh Hokage, upon Isshiki silencing the argument between her and the other Inners and asking on what Koji was doing, she reported that Koji was holding off on retrieving Kawaki to study Boruto after learning that the boy obtained his own Kāma. Smirking at this development, Jigen deduced that Momoshiki was behind this. Later, he transported himself to the dimension containing a Ten-Tails, and began speaking nonchalantly to it. Failing to eat his vessel, Isshiki comments on it being too soon as needed to complete his vessel, before absorbing its chakra using his Kāma. Afterwards, Isshiki intended to visit Boruto and Kawaki.

While attempting to capture Kawaki from Naruto Uzumaki's household, Jigen transported Naruto to another dimension with the intent of abandoning him there to die, but was attacked by Sasuke. During the ensuing battle Jigen was driven back and resorted to unleashing the full power of his Kāma, manifesting Isshiki's personality. As he quickly overpowered Naruto and Sasuke, pummelling them into submission, Jigen's body began to break down, which frustrated Isshiki as he disabled Naruto and Sasuke with giant black rods and reaffirmed his dire need to possess Kawaki. Revealing the crater acting as their battlefield was actually a gigantic coffin, Isshiki intended to kill Sasuke as he could escape any time and seal Naruto and Kurama within it, as he couldn't exert the power needed to kill Naruto due to Jigen being weakened. Sasuke escaped with Naruto's help and Isshiki brushed off Naruto's insults and revealed he was never interested in him as Kurama noted and that he was after Boruto for his Kāma, promising to kill Naruto if he escaped as Isshiki successfully sealed Naruto within the coffin, which he shrank to a normal size. Before teleporting away, Isshiki cursed Jigen's weakness as a vessel.

Having returned to Kara's headquarters, Isshiki had Amado treat Jigen's body, with the scientist informing him that it would take two days to fully recover. Excited as the progression of Kawaki's Kāma, he believed that it was due to exposure from Boruto's own mark. From this, Jigen strongly believed the two of them would become "perfect" Ōtsutsuki and form a God Tree to consume the planet. He also assured Amado that everyone would get what was promised. Later, while he had only returned to ten percent of his power, he received a report from Code who he had sent to guard the Ten-Tails. Afterwards, he was approached by Koji whom he asked for a report from. Informing Kawaki wasn't recovered, Koji questioned why he was tasked with the mission when Isshiki could have teleported to his location. Justifying his actions, Isshiki accused Koji and Amado of crashing the airship carrying Kawaki to allow him to escape.

Questioning his motives, Koji attacked Jigen, leading to the two fighting and Isshiki being informed Koji wanted to kill him. As Isshiki continued to repel Koji's various assaults, he voiced that the latter was nothing but a tool, having committed himself so fully to one goal. As Koji continued his attack while Isshiki fully unleashed his Kāma, he eventually caught Jigen off-guard, summoning a giant wall of flames. As Jigen failed to absorb them, Koji explained that he summoned naturally occurring flames void of chakra, meaning the mark was powerless before it as the flames began to consume him. Jigen tried to shrink the flames, but he could not maintain it for long due to his body reaching its limits. As Jigen's body was killed, and Kawaki's Kāma had yet to fully decompress, Isshiki was forced to fully reincarnate using Jigen as an imperfect vessel. He instantly shrunk and dispersed flames around him. Isshiki began shrinking various targets around him, forcing Koji to dodge. Ultimately, Isshiki's assault destroyed Koji's mask, revealing him as a clone of Jiraiya created by Amado.

Isshiki openly commended Koji and Amado's manipulations, having forced him into using an imperfect resurrection that was slowly killing him. At the same time, Isshiki viewed Koji as a fool himself, having been made as a sacrificial pawn, knowing that Koji would have no chance of defeating him. Koji brushed him off and entered Sage Mode. The increase in power let Koji hold his own against Isshiki for a period, but he ended the battle by summoning massive stones pillars to crush Koji's left arm and flank. As Isshiki mocked Koji's existence, he summoned a toad to allow for a retreat. Deciding not to waste any time as his body would fail in two or three days, Isshiki immediately teleported to Konohagakure to rebrand Kawaki with a Kāma.

Upon casually entering the village, he paid no concern to other shinobi. He was quickly intercepted by Naruto, shocking Isshiki by the Hokage's escape from his seal. He demanded for Kawaki. When Naruto refused, Isshiki began shrinking various structure to destroy the village. Naruto quickly attacked him at full power, but Isshiki calmly overwhelmed Naruto. Ultimately, a timely assist from Sasuke's Rinnegan saved Naruto. Isshiki found their efforts pointless as Sasuke began throwing shurikens recklessly, only for Isshiki to shrink them all. Sasuke then launched his sword at Isshiki. When he failed to shrink it, it was revealed to be Boruto transformed. He activated his Kāma and teleported Isshiki and himself to a separate dimension. Shocked by how much Boruto could wield of Momoshiki's power without proper training, Isshiki soon found himself joined by Sasuke and Naruto to help Boruto.

As the Konoha-nin faced down Isshiki, he focused his attention on Boruto. He grabbed Boruto and took to the air. Isshiki was intrigued by how far Boruto's Kāma had matured in such a short period of time, and even more curious as to how much power the boy could wield. Sasuke swapped places with Boruto, but Isshiki blocked Sasuke's attack and kicked him aside. Isshiki felt it best to present Sasuke and Naruto's corpses to the village to get Kawaki's location. The fight resumed, with Naruto and Sasuke's team-work managing to push Isshiki on the defence as he began shrinking all their attacks. However, Isshiki demonstrated a new technique, manifesting and manipulating massive black cubes that separated the duo. Isshiki pinned down Sasuke and moved to kill him with his own sword, only for Boruto jump in the way, causing Isshiki to hesitate. Boruto got Sasuke to safety, and deduced Isshiki couldn't kill him much to his fury.

While Isshiki tried to deny such a claim, Boruto revealed that Boro previously noted that Boruto's Kāma would be of a great aid to Kara's plans, meaning Isshiki needed Boruto alive. Realising his theory to be right from Isshiki's silence, Boruto threatened to kill himself with a kunai if he didn't back down. Isshiki however shrunk the kunai out of Boruto's hands and quickly subdued him, knocking Sasuke out in the process. Isshiki explained that once Boruto has fully transformed into an Ōtsutsuki, he would be feed to the Ten-Tails to nourish it into a God Tree. Suddenly, Naruto knocked Isshiki away from his son. While Isshiki offered to leave them alone for now if they handed over Kawaki, Naruto decided to use a last-ditch strategy of transforming into a new chakra form.

Trivia

 * Like other male members of the Ōtsutsuki clan, Isshiki was named after a Japanese folk hero whose name includes "Tarō", in this case Issun Kotarō, a hero from Japanese folklore who was only an inch tall, popularly known as Issun-bōshi. As a boy he went on an adventure to rescue a girl from an ogre, triumphing after being swallowed by it and using his sword — a needle — to attack it from within. He then claimed the ogre's magic hammer, Uchide no kozuchi, and used it to transform into a full-sized adult.

Quotes

 * (To Koji Kashin) "All genes… all people have a predestined fate. That man bore a mighty fate… a star of change. Now I understand. Amado had wanted to cling to it, to that man's mighty fate, to the minuscule possibility of change… Koji Kashin, clone of Jiraiya of the Sannin. That you shall die here, was also predestined by your genes!"