Kāma

Kāma is a seal that takes the shape of a black diamond on the user's palm. Although unfamiliar to the population at large, Kara has gathered intel on it and similar seals. Koji Kashin implies that Kāma can be obtained by killing a member of the Ōtsutsuki Clan.

There are two confirmed wielders of Kāma: Boruto Uzumaki, who received the mark after defeating Momoshiki, and Kawaki, who received it through unknown means, though Jigen also bears a similar mark on his chin.

Usage
After unconsciously activating it, Boruto was capable of absorbing ninjutsu. As it was his first time accessing his Kāma's power, it made him collapse afterwards. Three years later he could activate it at will.

Kawaki is able to absorb flames and cause large-scale explosions with his Kāma. However, using it causes his body to overheat, leaving him unconscious. Three years later, he is able to willingly activate it as well.

Boruto's and Kawaki's Kāma exhibit when in close proximity. When their Kāma resonate, it apparently enables them to release anything that either of them had previously absorbed.

Trivia

 * Although the kanji itself would normally be translated as, the furigana indicate the reading . "Kāma" means "wish", "desire", or "longing" in Hindu literature. In Japanese it is also an uncommon way to write "karma".

pt-br:Kāma Karma Kāma