RedHood101OUTLAW

It's similar to Sasuke's curse mark, basically. It's not Naruto and Kurama and will never be Naruto and Kurama because it's stupid and doesn't make sense. Boruto gets an increase in his physical capabilities (speed and strength), jutsu strength, and the ability to absorb chakra-based attacks. Supposedly, he also gets the Momoshiki's unique Rinnegan ability, where he absorbs a chakra-based attack and throw back an amplified version of what he just absorbed. Eventually, it's revealed that >!the Karma also gives the vessel the millennia of battle experience of the Otsutsuki, called "the true essence of Karma."!< The main purpose of the Karma is so that Momoshiki can revive in Boruto's body. As soon as the mark is implanted, the process begins and we don't know exactly how long it takes for it to finish. Over time, Boruto's DNA will be replaced by Momoshiki's DNA, and will automatically revive Momoshiki once it reaches 100%. Momoshiki also has the ability to possess and take over Boruto, initially when his chakra is low but eventually whenever Boruto accesses the "true essence of Karma" For Isshiki's case, he had two vessels: Jigen and Kawaki. Jigen is an unsuitable vessel, he can put a Karma on him, but cannot properly revive on him because he is then put on a time limit before his body crumbles. Kawaki is a suitable vessel, the body that Isshiki NEEDED to revive in, in order to not have the time limit. Jigen's Karma had already been at 100%, and is ready for Isshiki to revive. Why did he not revive when it automatically happens once it reaches 100%? Isshiki was still alive, living in Jigen's brain. When Koji burned Jigen, Isshiki also died, which kicked in the revive. Dead vessels while their Karma is at 100% can still be used to revive, which is why Isshiki was able to revive in Jigen. What makes a suitable vessel? We currently don't know. If a vessel is unsuitable, they experience a seizure and die. How did Jigen not die when he's an unsuitable vessel? Isshiki slowly turned his body into a body capable of bearing a Karma (which is why he's in Jigen's brain, he's also fully in control of Jigen's body and mind), yet cannot be a suitable vessel. When an Otsutsuki revives in one vessel, all Karma that's currently implanted in vessels disappear, to avoid duplicates of the same Otsutsuki existing. Currently, the only way to stop the Karma's process is to kill the vessel before it reaches 100%,>!which forces the Otsutuski in a dilemma of using their own DNA form the Karma to repair the vessels body, thus reviving them, where the Otsutsuki cannot revive but their soul persists, or they let the vessel die and therefore they die as well.!< Hefty explanation, hope I didn't leave some out and hope I cleared some stuff up.