Isshiki Ōtsutsuki

was a member of the Ōtsutsuki clan's main family who originally came to Earth with Kaguya to plant a God Tree and harvest its chakra fruit. He was betrayed by Kaguya, who left him for dead, and took over the body of a novice monk named Jigen, who he also branded with a Kāma. Centuries later, he became the leader of Kara as Jigen in order to continue to carry out his original plan, as well as secure a new, better vessel in Kawaki. He was forced to ressurrect in Jigen's body, and died without being able to apply a new Kāma, leading to his soul being extinguished, but not before entrusting his failed vessel and loyal follower Code with carrying on the Ōtsutsuki Will.

Background
A thousand 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.

Upon the formation of Kara, Isshiki through Jigen became its leader and acquired a new Ten-Tails seedling; the Inners collectively agreed on obtaining the Chakra fruit by cultivating a new God Tree huge enough to devour all life on Earth. 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. Passing on reviving himself through Jigen as his body would die within a few days as it wouldn't 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. With this intent, Isshiki began preparing for a new vessel to embed another Kāma seal once he fed Jigen and himself to the beast.

Eventually, Isshiki found Kawaki; after Delta tested the boy's blood as a viable candidate to be a vessel in the anime. Jigen approached Kawaki's abusive father with a large sum of money, to buy the boy for his plans. After taking custody of the boy, Isshiki introduced Jigen as his new father and reassured him. Eventually, Isshiki found Amado Sanzu, a scientist who endured several failings to revive his daughter Akebi. Recognising the man's talents, Isshiki offered him a place in Kara with the promise of reviving Akebi through the Chakra Fruit. Upon joining Kara, Isshiki had Amado use the remains of Shibai Ōtsutsuki to implant various powerful abilities into the members of Kara. He also had Amado modified Isshiki's vessel with Scientific Ninja Tools, the two attempted to transfer Kāma to Kawaki, Code and thirteen other boys in an experiment. Kawaki was the only success, while Code gained an incomplete White Kāma and the other thirteen perished. 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. Meanwhile, Code was recruited as his most loyal subordinate. At some point, Amado presented to him several cyborgs he had modified to secretly bring down Jigen, under the pretences of being useful for the sake of Kara's plans; however as their combat abilities exceeded Jigen's, he ordered Amado to dispose of them to not undermine his position as leader and ordered Boro to get rid of them, not knowing that Boro had actually hidden them all in his cult.

In the anime, another Inner Ōga was enhanced to help Amado with his research on the human heart. When she attempted to study Jigen's, he considered it treason, and destroyed a portion of her brain before she escaped.

Personality
Isshiki was driven, pragmatic, and remorseless. Common with the rest of his clan, Isshiki didn't care about the lives of others that he destroyed, no matter the number, in the quest to fulfil his own goals and desires or simply to live. He crushed Jigen's mind and completely took over his brain and body even when Jigen proved insufficient as a proper vessel for his revival. Even as he began overstressing Jigen's body with his immense power, he mocked Jigen's tears of pain, declaring him a worthless and defective vessel. Fellow clansmen were also expendable by him, as he intended to sacrifice Momoshiki's vessel to cultivate a God Tree. Like other Ōtsutsuki, he openly viewed himself as a superior being, looking down on all others as beneath him. In battle, he outright mocked enemies, repeatedly insulting his foes upon overpowering them and relishing in their awe and/or fear of his power. He also showed an authoritarian nature, fully capable of commanding respect among the group, to the point even the prideful Victor and hot-tempered Delta were easily silenced by him. He was also shown to be rather vain, storing various trinkets in his pocket dimension, including clothing and glasses of wine. In the anime, he noted to find certain people amusing, such as Deepa making him laugh on occasion, though he seemed to not express such emotions openly, as Amado did not think he was capable of laughter.

He was very confident in his abilities, bordering on arrogance. When he faced Naruto and Sasuke, the well-considered two strongest shinobi in history, he was completely unfazed by this. However, this self-confidence didn't prevent Isshiki from praising his opponents and also remaining calm when cornered, even actually praising them for revealing and figuring out the weakness of his abilities. Likewise, he was willing to admit when he was outwitted, openly declaring Amado's victory in forcing his resurrection in Jigen's body. He was 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, however he could only be worried that his future body would be imperfect. Despite his confidence, he was cautious, having ordered Amado to dispose of all the cyborgs that surpassed Jigen's powers to prevent usurpation of leadership, leaving only Code as an exception due to his loyalty, but not without installing limiters in him.

Isshiki was a hypocrite and an abusive parental figure, as when he took in Kawaki as an adopted son and promised him safety, he placed the child, alongside fourteen others, in a dangerous experiment that led to thirteen of them dying outright. His methods of training Kawaki in becoming his vessel, along with discipline for disobedience, amounted to constant physical abuse and neglect, beating the child while refusing to explain to him of the true purpose of the seal he placed onto him. Isshiki's horrible parenting greatly warped Kawaki's personality with violent tendencies and trauma.

Despite his amoral nature, Isshiki was shown to be able to remain calm even when faced with insult. Generally, Isshiki was 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 preferred to only incapacitate enemies when not needing to kill them and even willing to avoid conflict if potential adversaries were agreeable to his terms. As with Momoshiki, Isshiki's confidence and manners stemmed from an extreme superiority-complex. As such when faced against the prospect of an opponent who can actually challenge him, he became furious and determined to restore his self-perceived dominance.

He seemed 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 was 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 had shown an irritable side, as when tasks fail to reach his expectations, he could lash out, as he kicked a broken tank after another setback to his plans. Prioritising his own survival more than almost anything, Isshiki lost his composure when Naruto drained him of his already limited lifespan, showing his fear of a permanent death and his rage at Naruto's mockery. He made it clear that Kawaki would not amount to anything but as a sacrifice for Isshiki's own survival, and upon being outsmarted by Kawaki, a dying Isshiki, losing all composure, expressed pure horror at his own death. Also, despite his vain attitude, he could genuinely appreciate those who are faithful to him, as he regarded Code as his most beloved, loyal subordinate, naming him his successor to the Ōtsutsuki Will.

He viewed those who value peace as the utmost priority as being cowardly and foolish. Arrogant as he appeared, Isshiki was 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 fooled all the Inners so well that he ultimately tricked Koji and Amado to reveal their true intentions of killing him. Even though Victor went to falsify evidence to blame Deepa of his unauthorised project to recreate a God Tree, Isshiki did not trust any of it and while putting Victor off guard by seemingly letting him off with a warning, instead revived Deepa's head to confirm the truth and ordered Victor's execution.

Isshiki was so driven in his goals that he could 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 left him to have little to no interest in other matters, willing to leave his defeated foes alive if he deemed it taking up too much of his time. Isshiki's devotion in cultivating the Chakra Fruit was 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. Still, he would do whatever he deemed 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 to ensure he would not die in anyway outside of being fed to the beast, in order to produce the highest calibre of Chakra Fruit.

Even after death he was determined to continue his clan's way of evolving by tasking his most loyal and trusted subordinate Code to follow in his footsteps and become an Ōtsutsuki by planting a new God Tree on Earth and consume a chakra fruit, and then to continue to do so across more planets. He was also vengeful, naming all those who led to his death for Code to kill.

Isshiki seemed to believe that all living beings have their fates predestined by their genetics, as he stated that Koji, a clone of Jiraiya, was 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 were 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 or tomoe 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 fingernails and toe nails were painted a deep black.

Isshiki preferred 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 his bare muscular torso, 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 so was vast that while limiting himself in Jigen, he could pressure both Naruto Uzumaki and Sasuke Uchiha, the two strongest shinobi in history simultaneously and who previously together overpowered the chakra enhanced Momoshiki Ōtsutsuki, and then decisively defeat both of them once exerting himself more. Likewise, upon exerting too much power, despite the various enhancements Jigen gained to be monstrously powerful in his own right, had difficulty containing it before breaking down. 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.

Chakra and Physical Prowess
Isshiki was a very resilient man, able to survive being bisected long enough to find a new host. While possessing Jigen, Isshiki displayed incredible prowess in 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 was 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 also had 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 were 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, casually toying with him during their battle before finishing him off, and was able to attack Sasuke, with his Sharingan being unable to track him fast enough.

Isshiki wielded tremendously powerful chakra, compared to Naruto in his Six Paths Sage Mode form by Kawaki. Its sheer reserves and strength at full power was 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 was so massive that it required 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 believed three days would be the limit.

Ninjutsu
Like the other members of his clan, Isshiki could hover and fly at high speed. Utilising Yin Release, he could, using genjutsu, project an image of himself from vast distances — even across dimensional planes. He had shown considerable bōjutsu prowess, being able to easily counter the masterful swordsmanship of Sasuke. He could 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 was also a gigantic coffin, with its lid suspended above the clouds. He could also use the massive construct to perform a powerful fūinjutsu, able to seal away even the likes of Naruto. Only Isshiki himself was capable of breaking the seal and cracking it would only destroy whatever is inside. In the anime, he could also produce powerful, fire blasts from his hands.

Kāma
As an Ōtsutsuki, Isshiki could 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 abilities and chakra levels, as well as the ability to absorb chakra. While using a vessel with its enhanced Kāma, Isshiki displayed 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 was also resilient enough to be completely unfazed while being burned by Amaterasu, which could harm even Tailed Beasts, proceeding to calmly absorb it. He could also connect space between two targets bearing his mark to instantly teleport to the other target.

The true purpose of Kāma was 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 from Kaguya's attack, but knowing Jigen's body would die days later after 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. Isshiki would still have to nurture Kawaki's through arduous training to ensure he could resurrect in his body.

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.

Having left a White Kāma on Code, Isshiki's spirit was able to temporarily manifest via it to speak his final words to his failed vessel before disappearing.

Dōjutsu
With his unique right eye, Isshiki was able to view the lifeforce of living things — including his own — in the form of fire-like shadows and perform Sukunahikona, a Shinjutsu technique that allowed him to instantly shrink himself or anything non-living target he saw and just as quickly restore its original size. After shrinking a target, he could use Daikokuten, which let him store any of his shrunken targets into a pocket timeless dimension, which he could summon at full size at any given time. He tended to make regular usage of this, manifesting replacements of destroyed furnishings and other items, like a table, food and drink, and even lit candles. Isshiki could manifest these objects anywhere among his surroundings as well as freely manipulate them once brought forth. He could use these abilities 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. He could even reduce the size of buildings to cause severe collateral damage and remove stable footing from his enemies.

Having the ability to produce and summon a myriad of special black rods, his most common tactic with them were to instantly summon black rods at various sizes and in great quantities to impale his foes with tremendous force, enough to pierce Naruto's chakra shroud. Sending in a barrage of those rods was enough to detroy small cliffs. Isshiki's rods were durable enough to evenly clash with Naruto's Rasengan. The rods were noted for having the ability to drain the chakra from anyone pierced by them. Varying in size, the rods could rival the size of a Tailed Beast and Susanoo. He could also manifest massive black cubes which disrupt sensory abilities.

As an Ōtsutsuki, Isshiki possessed a Byakugan, but apparently only in his left eye and couldn't access it when in a vessel. It granted 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, and Sasuke's mineral-based smoke bomb.

Intelligence
Unlike other members of his clan, who had little to no knowledge about shinobi and their abilities due to being largely unaware of their existence, Isshiki possessed vast knowledge about the history and potential of shinobi and humankind altogether due to having lived on Earth for a thousand years. Having centuries of experience and knowledge, Isshiki openly shared his knowledge about his opponents' abilities and attacks, even mid-battle, both in an attempt to demoralise them by noting their flaws before effortlessly countering them, as well as due to his arrogance of believing that nobody could surpass him.

Isshiki was also aware of the full concept of tailed beasts, and their abilities, as well as the Susanoo, noting that while having great defence (which Isshiki was nonetheless able to effortlessly break through), it possessed little speed, which he used to his advantage. Despite his arrogance, Isshiki was not above studying and learning about his opponents and possible threats, as he was fully aware of the reputation of Naruto Uzumaki, Sasuke Uchiha, and even the deceased Jiraiya, whose clone Amado deployed against him.

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.

After a failed plot to grow another God Tree, Isshiki held a private meeting with Victor, who claimed Deepa to be responsible. While voicing suspicion of his claim, Isshiki let Victor off with a warning.

Ao Arc
In the anime, Isshiki contacted Amado to discuss the development of Kawaki, knowing that he was already into Phase 3 of their plans. Amado insisted that while it was technically true, the data was still too weak to continue with Phase 3. Isshiki decided to transfer Kawaki for a field test. Victor then appeared, offering his new stealth blimp for the transfer. Later, despite the smooth moving of Kawaki onto the blimp, there was a malfunction, causing the blimp to crash, which Isshiki was alerted to.

Isshiki held a meeting with the other members 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. In the anime, not trusting Victor's story about the mishap in the Land of Valleys being caused by Deepa, Isshiki had Deepa's corpse recovered and Amado restore his brain to learn the truth of Victor's betrayal. No longer needing Deepa's remains as a liability, Isshiki had Amado dispose of Deepa and had Koji Kashin go kill Victor. During a physical checkup on Jigen's body from Amado, Isshiki revealed his suspicions that the blimp's crash wasn't Victor's doing, but rather a third party took advantage of Victor's betrayal to mask their own actions. Amado said he would investigate it.

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 not even returned to ten percent of his power, he received a report from Code who he had sent to guard the Ten-Tails. In the anime, Delta reported to him that Boro had been killed by someone and that the Hokage had escaped. He assigned her to destroy Boro's cult base, which housed a Space-Time Gate. Later, Isshiki 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 shuriken 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 shinobi faced down Isshiki, he grabbed Boruto and took to the air. Intrigued by how far Boruto's Kāma had matured, Sasuke swapped places with Boruto, but Isshiki blocked Sasuke's attack and kicked him aside. With Naruto and Sasuke's team-work, they managed to push Isshiki on the defence as he began shrinking all their attacks. However, Isshiki began 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, leading to Boruto suspecting Isshiki didn't want to kill him. While Isshiki tried to deny such a claim, 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 fed to the Ten-Tails to nourish it into a God Tree. Suddenly, Naruto knocked Isshiki away. 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 form, with which he began pressuring and overwhelming Isshiki.

In time, the strain of Baryon Mode began catching up with Naruto, allowing Isshiki to comprehend its life-draining aspect. However, Isshiki began spitting up blood, and realised that Naruto's new power also drained his life-force when they made contact. Naruto continued to attack Isshiki, who managed to take advantage of his chakra connection to Kawaki's prosthetic hand to teleport him to the field before his time ran out. As Kawaki tried to escape Isshiki, he opted to use Kawaki's love for Naruto against him, assaulting the downed Hokage. Kawaki ultimately showed himself and attacked using the ninjutsu Naruto taught him. Isshiki easily overpowered it and branded Kawaki again, smugly declaring his victory, only to see the mark disappear. As the horrified Isshiki asked how this was possible, Kawaki was revealed to be only a shadow clone, making him insufficient to host the Kāma. Finally, Isshiki's time ran out and he crumbles to dust, leaving Kawaki deliver the killing blow as he crushed his disintegrated form into ashes.

Despite his demise, ever defiant, Isshiki's soul made contact with Code through his White Kāma. Isshiki informed a grief-stricken Code about the events that led to his death. Before finally departing, Isshiki ordered Code to carry on the will of the Ōtsutsuki clan. He told Code to capture either Boruto Uzumaki or Kawaki and feed them to the Ten-Tails and devour the God Fruit to become an Ōtsutsuki himself and continue evolving. Accepting Isshiki's final decree, Code asked to know the names of those who killed Isshiki so Code could avenge him. Isshiki told him the names before fading away from the land of the living for the final time.

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!"
 * (To Code) "Kawaki or Boruto Uzumaki. Consecrate either of them to the Ten-Tails and cultivate a God Tree. Then procure the chakra fruit that the God Tree bears. It is the crystalisation of a planet's life. It shall contain everything. A record of all life that ever lived and died on this planet, including me. Eat it and upgrade yourself, Code. Do that, and you yourself will become a new Ōtsutsuki. Then go forth and devour planet after planet across space. Keep evolving until you become a peerless, unique existence. A god. That is the Ōtsutsuki Will that you shall inherit, Code."