Jigen

is the leader of Kara.

Background
During Kawaki's childhood, Jigen bought the boy from his father with a large sum of money. After taking custody of him, Jigen introduced himself as Kawaki's new father, while telling him he could make himself at ease now. He would later attempt to transfer Kāma to Kawaki and fourteen other boys, with Kawaki being the only known success and thirteen dying outright. Jigen put Kawaki through gruelling training so he'd master the Kāma, and would constantly berate him as only having value as a vessel for the Kāma, striking the boy whenever he questioned him.

Personality
Jigen appears to be formal and courteous, addressing the fellow members of his organisation politely before beginning their meeting, and even extends his manners to his enemies, as he politely greeted Naruto Uzumaki, and apologised for having not undid his shoes when in the Uzumaki's household (in most Asian cultures, it is customary to remove your shoes before entering a house). He does have a serious and authoritarian side to himself, as he is fully capable of commanding respect among the group, to the point even the prideful elderly Inner and hot-tempered Delta are easily silenced by him. 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. While apparently less confrontational than Delta, as he tried to only incapacitate Naruto rather than fight him, he is shown to be very confident in his abilities, calmly declaring his intentions to eliminate the Seventh Hokage for his interference. 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 is also shown to be a perfectionist, viewing his work on Kawaki and his Kāma as work of great importance, disgusted to see his adopted son's damaged right arm using a prosthetic and quickly voiced his intention of restoring Kawaki's arm.

He is also shown to have a very amoral and remorseless side, caring not in the slightest at how many innocent lives he must sacrifice to obtain his goals. His single-minded nature views all his actions towards Kawaki, no matter how harsh, as truly in his best interest. Apparently, he views a peaceful world as foolish, likewise feeling the same way about Naruto Uzumaki. Although he appears arrogant, Jigen is very cautious and secretive, capable of keeping the full scope of his abilities secret even from his allies. He's very perceptive and deceptive, as he had suspicions about Koji Kashin's loyalty, yet still hid it fully from the other Inners, feigning complete trust to the point of admonishing Delta for not following Koji's way of executing the mission of retrieving Kawaki, and was able to easily trick him into revealing his desire to know Jigen's secrets.

Appearance
Jigen has dark long hair tied in a ponyhawk style, a broad nose and large black pupils. He bears a diamond-shaped marking of Kāma on his chin and piercings. Below his left eye, he has a Roman numeral "Ⅳ" tattooed. He wears a black hooded cloak, along with light-coloured capri pants and sandals.

Abilities
Being an Inner of Kara, specifically as the organisation's leader, Jigen is regarded by Kawaki as being a complete monster in terms of power and ability. As the leader of Kara, he is the most powerful member of the organisation. His surpassing power is shown by how Koji Kashin deemed the level of strength showed by Naruto, well-regarded as the strongest ninja in history, even after his decisive victory over the fellow Inner Delta as being insufficient to defeat Jigen. In addition, Sasuke Uchiha, credited with being Naruto's peer in power, was greatly unnerved upon seeing a display of his power, deeming the inevitable fight with him a far more dangerous situation than he expected, and chose to retreat rather than engage him. Upon arriving at Konoha, he easily subdued Naruto in his base form and effortlessly restrained Kawaki with his Kāma activated. Ino Yamanaka, who had earlier remained unfazed by Delta's presence, was instantly terrified upon sensing Jigen's chakra to the point she almost collapsed, describing it as incredibly sinister, and felt the need to have Naruto backed up by the Police Force when Naruto told her that he would fight Jigen by himself.

Jigen apparently excels in genjutsu, as he was able to use it as a means to communicate with many over a large distance at once. Jigen also has considerable senses, as he was easily able to sense the presence of Koji's toad that went unnoticed even to Naruto.

Ninjutsu
Though Jigen appears to cause objects to vanish and reappear from thin air, he in fact possesses the unique ability to rapidly shrink matter to microscopic levels, and can return it to its original size just as quickly. In battle he utilizes this ability to launch microscopic black rods into the bodies of his foes, which then inflict catastrophic injuries and drain chakra from the victim when returned to their original size. He can also apply the ability to his own body, allowing him to disappear from sight and maneuver around the battlefield, almost as if teleporting. The limitations of this ability remain unknown, but Sasuke was able to track his movement even at a microscopic level thanks to the Sharingan. Outside of combat he also uses the technique for more mundane purposes, such as replacing home furnishings destroyed by Delta. The technique may have also been utilized in developing the microscopic Shinobi-Ware implanted in Kawaki and Delta.

Apart from that, he can travel through dimensions with space–time ninjutsu and levitate in the air, feats which he can also perform in his microscopic state.

Physical Prowess
Jigen appears to be an extremely skilled melee-combatant, both with weapons and hand-to-hand combat, having personally brutally trained Kawaki into becoming a specialist in close-quarters combat. He has shown tremendous speed and strength, easily kicking Naruto away, impressing the Hokage with his reaction, and effortlessly caught a punch from Kawaki when he had Kāma activated with a casual grip, even effortlessly causing Kawaki visible pain by merely lightly twisting his arm. He is also highly durable, suffering no injuries from a kick to the jaw from Naruto in his Six Paths Sage Mode.

Kāma
Jigen possesses a Kāma mark on his chin, which he can activate at will, causing it to spread across his entire body in nearly symmetrical sunburst patterns. The nature of its power is unknown, however, he has been shown to have the ability to pass Kāma on to other individuals through the aid of science, albeit with a low success rate, more often resulting in death. Jigen is also skilled enough in its usage to have taught Kawaki how to properly use its power, with Kawaki noting he knows everything about Kāma. Jigen is skilful enough with its absorption powers to absorb chakra from tailed beast-like entities, and his ability to absorb large quantities of chakra is unaffected even while in his microscopic state. In addition, he has the ability to synchronise with Kawaki's Kāma, using it as a portal to teleport to his current location. When his Karma progresses far enough, a horn protrudes from his left temple and wraps around the back of his skull, resembling a crown.

Ao Arc
Upon his organisation's vessel being lost, Jigen 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, Jigen 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 Jigen gave her permission to partake in the recovery of the vessel. Later, after Delta's decisive defeat by the Seventh Hokage, she reported that Koji was holding off on retrieving Kawaki to study Boruto Uzumaki after learning that the boy obtained his own Kāma. Smirking at this development, Jigen deduced that Momoshiki Ōtsutsuki was behind this.

Later, Jigen went to an undisclosed location accessible only through space–time ninjutsu to see an immobilised beast. He spoke nonchalantly to it, hovering above and addressing it as Ten-Tails. The "Ten-Tails" tried to eat Jigen, but failed to do so as Jigen was out of reach. Jigen stated that it was too soon as he needed to complete the vessel. Jigen then used his Kāma to absorb more of its chakra and his physical form changed into an Ōtsutsuki who supposedly partnered with Kaguya Ōtsutsuki briefly. After absorbing the beast's chakra, Jigen intended to visit Boruto and Kawaki.

Using the connection between his and Kawaki's Kāma, Jigen teleported to Naruto Uzumaki's house instantly to bring back Kawaki. He noticed Koji's toad and watched suspiciously as it was incinerated by Koji before apologising to Naruto for his rude arrival. When Naruto rebuked his politeness with hostility and attacked him, Jigen easily subdued Naruto by pinning him down with rods and proceeded to easily restrain Kawaki and tried to reason with his wayward adopted son, noting how his prosthetic arm was merely a tracking device no different than Kāma, to him a disgusting object that he would fix when they returned to the base, and that the village was merely using Kawaki as a bait for Kara. Kawaki's Kāma activated and a horn grew out of it, surprising how much the mark advanced. Naruto then kicked him away and Jigen, seeing his foe won't back down, activated his Kāma to begin fighting the Seventh Hokage, intent on killing him for his interference.

Trivia

 * Among other things, "Jigen" is the word for the.