Boro

was an Inner from the organisation Kara.

Personality
Much like other members of Kara, Boro carried himself with a very confident, if not smug, attitude. Upon facing the various abilities of Team 7 and Kawaki, he faced them down in a very condescending natures, viewing their efforts as pointless. Additionally, he was also shown to have a teasing side, mocking Delta over her defeat at Naruto's hands and stating he wanted to see her down face. Also a committed man, he remained vigilant in his mission to safeguard the sealed Seventh Hokage. Very knowledgeable, Boro is shown able to quickly determine and handle most threats with little shock. As with Jigen, he was devoted to Kara's goal, and was uninterested in other matters such as Mitsuki's attempts to attack him, even being willing to let him escape had he not continued to attack him, but became ever more grateful for Boruto's status as Momoshiki Ōtsutsuki's vessel, desiring to capture him for Kara's benefit. Like with Delta and Jigen, he saw Kawaki's attachment to Konoha as being a weakness in their coveted vessel and expressed his desire to retrain him from scratch as soon as he brought Kawaki back. When his core was destroyed by Sarada's Chidori and his body began to mutate, he lost his composure and went into an insane rage, attacking anyone around him with wild swings.

Appearance
Boro was a tall middle-aged man with a heavily-built frame. He sported a white blueish beard and moustache and eyes, and had a trio of tattoos on his face that appear to form the Roman numeral Ⅲ. He also had a disk embedded on both sides of his temples, one on each of his pectorals, two on both his forearms, two on his shoulder-blades, and two at his hips. His body was also apparently modified to be void of gender-based anatomy.

Like other Inner members of Kara, he wore a dark hooded robe. Beneath his robes, he wore a dark coat with a row of buttons on the right side; he tends to leave the bottom buttons undone. He also wear dark pants with high boots, and armbands with metal plates on the forearms.

Abilities
Being an Inner of Kara, Boro was regarded as completely monstrous in terms of power, noted as stronger than fellow Inner Delta. It was even stated that Boro would be one of the most likely to be sent next to retrieve Kawaki from Naruto Uzumaki after the strongest shinobi had just decisively defeated Delta. Kawaki claiming he was in some ways even worse than Jigen. Kara also held his abilities at a high enough regard that they had him guard the sealing coffin that held Naruto while expecting Sasuke Uchiha to save him. His might proved to be able to easily take on and overpower the combined might of Team 7 and Kawaki with his unique abilities.

Physical Prowess
Befitting his large stature, Boro was very strong, able to easily lift the massive sealing kettle that contained Naruto with a single hand and hurl it a great distance and could also easily break out of being restrained by Mitsuki's snakes and lift and smash him down with great force. He is deceptively fast, able to skilfully escape from his enemies' sights after creating a diversion and quickly intercept his opponent's escape. Boro's body is also highly resilient, able to take a direct hit from a Rasengan and easily remain standing as well as effortlessly shrug off being brutally smashed by Kawaki's transformed arm. Additionally, he shows great pain tolerance, able to take all of Team 7 and Kawaki's blows that landed that could destroy his body. He is also shown to be very proficient in taijutsu, able to easily fend off the combined assault Team 7 and Kawaki with punishing blows.

Ninjutsu
Boro is able to use Fire, Earth, and Water Release. By combining the first two, he can use Lava Release to create a potent acid and is also able to release smaller blasts that can still easily melt shuriken. With Water Release, he can produce surging walls that could easily repel Mitsuki Lightning Release: Snake Lightning, and Sarada's Fire Release: Phoenix Sage Fire Technique. He is also able to perform a regeneration technique that can rapidly undo all physical damage to his being and even negate the effects of poison. He has proficiency in shurikenjutsu, able to stealthily launch shurikens laced with gunpowder. He is also capable of accessing an alternate dimension through unknown means.

Scientific Ninja Tools
Like with all other members of Kara, Boro's body had been modified with scientific ninja tools by Amado, with which Boro was able to release a fast-acting virus in the form of a dark mist. This mist gradually paralyses his opponents upon contact, and as it is a form of physical matter rather than chakra, it cannot be absorbed by Kāma. Boro himself is immune to this virus due to carrying the antibodies for it in his bloodstream. Even if the virus is neutralised, he can mix it with gunpowder to instantly detonate it with the slightest spark. His body is also modified with a special core that he can migrate inside body, which serves to instantly activate and augment his healing technique, enough to survive virtually any damage and regenerate within seconds, even if his head is completely obliterated. At the same time, his modifications are dependent on the core to keep his body stabilised, as without it his body will mutate uncontrollably.

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

Ao Arc
Boro attended a meeting held by Jigen to discuss the urgent situation relating to the missing "vessel". As Jigen dispelled the genjutsu, he voiced that they must recover the vessel at all costs.

Kawaki Arc
Figuring Delta would be disheartened following her failed attempt at retrieving Kawaki, Boro laughed at her when she became frustrated. Shortly after, when he was informed Koji Kashin was observing Kawaki in Konohagakure, Boro questioned what the Inner was doing. Some time later, after Jigen has sealed Naruto Uzumaki in a tea pot in a foreign dimension, Boro watched over it. Shorty after, a group of children came into his vicinity, leading to Boro joyfully recognising Kawaki.

As the children prepared to fight the Inner member, Boro quickly displayed his might, changing the landscape with his Lava Release. As Kawaki absorbed the technique with his Kāma, Boro went for a sneak attack, which was absorbed by Boruto's Kāma. Boro was amazed to see another Kāma wielder. As Boro continued to endure Kawaki and Boruto's attacks and quickly heal, even from Mitsuki's venomous snake bites, he exposed them to his Dark Cloud, sapping away their strength. Boro expressed his delight in meeting Boruto, noting that Boruto's Kāma meant that Kara's time limit for completing their plans can now extended through Boruto as the vessel of Momoshiki Ōtsutsuki. While planning to take Boruto back to Kara along with Kawaki, the combined effort of Mitsuki and Sarada Uchiha gave the team an opening to retreat. Boro however remained calm, knowing they would return since their goal for coming here was the Hokage.

Soon after, Boro was approached by Sarada, who revealed to know the truth behind his Dark Cloud. Impressed at her insight, he quickly attacked her, forcing her on the defence as he worked to infect Sarada like the others. Ultimately, he caught and infected her. He began mocking her situation, but was surprised by her ability to launch a Fire Release: Great Fireball Technique on him and powerful punch. With Boro injured by the attack, Boruto and Kawaki also made their move, fully recovered from the virus, and obliterated the man's head. Boro however reacted in time to activate his regeneration technique before being hit, letting him survive and completely recover. Boro deduced that Mitsuki's snake took some of his blood and harvested the antibodies in it, giving the kids immunity to his virus. Impressed by their abilities, Boro decided he would have to throw them off their team-strategy and went for the sealed Hokage, tricking Kawaki into breaking formation.

Boro launched some shuriken at Kawaki, who blocked them, only for them to explode. Boro was amazed that despite being injured, Kawaki still moved to protect the sealed Hokage. Boro voiced his displeasure at Kawaki's new soft nature, he swore to have Kawaki retrained from scratch. The children continued their team assault on Boro, who repeatedly regenerated from everything that was done to him. As he began to beat down the exhausted foes, Sarada struck at Boro's core with her Chidori, having located it and learned of its significance for his regeneration from Kawaki. Successfully removing the core, Boro's body began mutating without its stabiliser into a massive and misshapen form. As Boruto and Kawaki used their Kāma to free Naruto from the seal, Boro managed to regain some control of himself, he turned his rage on the kids and quickly overpowered them. Suddenly, Boruto's Kāma evolved further, replacing Boruto's consciousness with Momoshiki's, who exhibited a massive boost in power to effortlessly destroy Boro.

Legacy
In his arrogance, Boro revealed a critical clue to Boruto about Kara's plans. Upon facing Isshiki, Boruto realised from Boro's words that Isshiki required Boruto alive to accelerate his plans for the God Tree.