Kimimaro was the fifth and final member added to Orochimaru's Sound Four, technically making them the Sound Five during his tenure. The original four didn't volunteer to accept him—he was forced upon them because his combat abilities were in a league of their own, surpassing all of theirs combined.
He's best known as the last survivor of the Kaguya clan, a bloodline capable of manipulating their own skeletal structure as a weapon. The clan was wiped out in a brutal attack on Kirigakure; they'd apparently assaulted the village for little reason beyond bloodlust, but severely underestimated their opponents and were slaughtered to the last member. Kimimaro alone made it out alive.
Orochimaru considered him the strongest the Kaguya clan ever produced, possessing "abilities that even that war-loving clan feared." This made him too dangerous to roam free—he spent most of his life locked in a cage and only released when Orochimaru needed him for specific battles against rival clans.
Like other high-ranking members of Orochimaru's organization, Kimimaro bore a cursed seal that amplified his power while compromising his autonomy. His level 2 form is particularly striking: dark gray skin, six massive bone spines jutting from his chest, and a long bone-spiked tail that gives him an almost dinosaur-like appearance. What sets him apart is his remarkable control—he could manipulate how much the cursed seal spread through his body without fully activating it, something most users couldn't pull off.
Fans often note that Kimimaro apparently had a friendship with Jugo at some point, and his cursed seal mastery impressed even him. Karin has said he was the only person who could restrain Jugo without risking serious injury.
NOTE: While some fans refer to him as Kimimaro Kaguya, the official second databook lists his name simply as Kimimaro.
Content compiled by AnimeList.moe from publicly available sources.
