Karma

After defeating Momoshiki, Boruto's right hand was forcibly marked with a four-point black diamond seal. Noted to have similar properties to Orochimaru's Juinjutsu, it is a genetic backup of the Ōtsutsuki which subconsciously allows Boruto to access the powers of Momoshiki. Its very presence on Boruto makes him potentially able to surpass his father Naruto, who is well-considered the strongest shinobi in history. According to Isshiki, Boruto has a rare compatibility for the mark, which has allowed him to instinctively develop and synchronise with it at an accelerated rate, and has progressed tremendously in the short time since obtaining the mark.

Once activated, the mark stretches and expands to cover his entire arm and the right side of his face in a series of elegant lines. While doing so, it greatly boosts his physical parameters and also lets Boruto absorb virtually any ninjutsu or energy-based target. Also, Boruto can produce a dimensional portal to other realms. Originally, he could not access the mark willingly and it takes a huge toll on his chakra but was later taught how to more efficiently by Kawaki. Even without proper training, Boruto was eventually able to utilise more of the mark's power with little struggle, something that even Isshiki found surprising. Isshiki notes that Boruto's strong and healthy body being compatible with the mark will enable the God Tree to produce the highest quality Chakra Fruit.

Boruto manifesting Momoshiki through his Kāma.

Despite its beneficial powers, the mark is in fact dangerous to Boruto's being, as gradually, Boruto's entire being is being rewritten as Momoshiki, and will eventually become reborn as him.[33] In moments of great danger his Kāma can progress further, fully manifesting Momoshiki's will and personality, allowing him to take control of Boruto's body and fight on his behalf, retaining access to Boruto's knowledge and skills. In this state, a flat horn protrudes from the right side of Boruto's forehead, curving up and back slightly. This also causes his right eye to become a Byakugan. His physical strength and speed increase dramatically, to such a degree that he could effortlessly destroy the mutated Boro's right arm and send his monstrous form crashing with a series of kicks. Momoshiki's manifestation gains access to flight and augment Boruto's techniques tremendously, able to unleash a massive Rasengan on the same scale as the Parent and Child Rasengan. Boruto's contact with Kawaki, who bears Isshiki's Kāma, created a resonance that accelerated the takeover rate of both vessels.