Kinka

is one of the two conjoined brothers who fight for control of a single body, a fight with his brother Ginka.

Powers
Kinka has shown to have an ability over fire, in contrast to his brother, who has control of lightning. He is also able to cover his body in fire when touched directly, causing whomever touches him to be burned.

Manga
For some time, he has been fighting his brother, Ginka, for control of their body which they share; as yōkai of their species are born with two heads, but the stronger head devours the weaker soon after birth, but so far, they have been unable to kill each other and only managed to wound one another. Somewhere along the line, he acquired an unknown weapon that blows flames and a shield. When Inuyasha and his friends came across the spot where the two brothers usually fight, Inuyasha tried to stop the fighting with his Kaze no Kizu, but the two escaped into the air and told Inuyasha and friends of their lifelong fighting. Before long, they began fighting again and the Saimyōshō appear (and Kanna told Mōryōmaru about the "power of their blood") and Kinka blows fire at the bugs (and possibly) tries to burn Ginka in the process. The two brothers start fighting again and the Saimyōshō are caught in the cross-fire, Ginka and Kinka then return home and Inuyasha's gang goes to their lair to try to kill them while they slept.

When the gang reach Ginka and Kinka's lair, they discovered Mōryōmaru and Kanna, who told Mōryōmaru that if he devoured the brothers, he would be bonded even more to his armor, when Mōryōmaru tried to kill the two while they slept, Inuyasha used the Kaze no Kizu to wake up Ginka and Kinka, and when they were awake, Inuyasha told them to escape. Inuyasha then turned to fight Mōryōmaru with his newly mastered Dragon Scaled Tessaiga and struck Mōryōmaru's right shoulder, in which Mōryōmaru was surprised that Inuyasha didn't get hit with a backlash of Yōki. Mōryōmaru then pierced Ginka and Kinka's joined body, causing them to bleed and some blood landed on Mōryōmaru. The blood then caused Mōryōmaru's armor to harden and pushed back the Tessaiga, then, Mōryōmaru turned his attention toward Ginka and Kinka, who attacked him, but to no avail. He then tried to shoot them down with the Kongōsōha ability he stole from Inuyasha. But Miroku used his Kazaana to try to suck up the Diamond Spears before they hit Ginka and Kinka, but the Saimyōshō appeared, which caused Miroku to withdraw his Kazaana, otherwise he'd be poisoned as Sango stated. Mōryōmaru also took notice and figured out that Naraku purposely helped Inuyasha strengthen the Tessaiga and sent Kanna to him, in hopes that Inuyasha and Mōryomaru would take each other out. Miroku and Sango then warn the brothers that Mōryōmaru plans to devour them both, and Mōryōmaru prepares to use the Kongōsōha again, but Inuyasha uses his own first. The spears prove ineffective against his armored body, but the spears manage to pierce the wings, sending Mōryomaru falling.

But as he's falling, his tendrils grab Ginka and Kinka and as they hit the ground, Ginka and Kinka reveal a new ability, in which they cover themselves in their respected element (fire for Kinka and lightning for Ginka) whenever touched directly. This ability damages Mōryōmaru from the inside and threatened to kill the Infant. Mōryōmaru then released Ginka but didn't release Kinka, as soon as Ginka was freed, he attacked his brother and Mōryōmaru stabbed Ginka from the back with his Kongōsōha arm, killing the demon of lightning. Mōryōmaru was then going to devour them, but Inuyasha saw the Kinka was still alive (just barely), and he tried to save them both. Mōryōmaru then grabbed Ginka's lifeless body and Kinka was finally separated from his dead brother, who was then devoured by Mōryōmaru. And Mōryōmaru even stated that it was their decision. Kinka, weakened, stated that Mōryōmaru was right and that he would do the very same if Mōryōmaru released him instead of Ginka, saying that they were born like that. He also stated that Ginka didn't have any ill-will toward him and would hold no grudge if he was burned by Kinka's flames. But he also said that the fight was only for him and his brother and attacks Mōryōmaru. But his flames didn't have any effect, as Kagome stated, that it might have only worked when Ginka and Kinka attacked at the same time. Suddenly, Ginka's lightning ability appeared, even though he was dead. It was then revealed that Ginka's powers awakened Kinka's powers as well. But then, Mōryōmaru stabs Kinka from the front with his Kongōsōha arm, stopping Kinka's attack and leaving him close to death. With his last once of strength, he flew up and was absorbed into Tessaiga, giving it his flame ability, and thus giving Inuyasha the "Flaming Tessaiga", which he used on Mōryōmaru, awakening Ginka's powers inside Mōryōmaru. After Mōryōmaru fled, the Flaming Tessaiga was never seen again.

Anime
In Episode 5 of InuYasha: The Final Act, Kinka and his brother played a somewhat similar role as they did in the manga. Kinka and his brother battle in the sky, missing each other's blow as Mōryōmaru watches and being told by the Infant that a strong power binds them and by obtaining that power would strengthen the link between him and his shell and to consume them as Mōryōmaru flies toward them. Once he's close enough, he shoots at their base causing them to bleed, which got their attention and their blood landed on Mōryōmaru which healed the crack on his shell (which were inflicted by Sesshōmaru in Episode 2) which surprised and amused Mōryōmaru as he drew near when both brothers shot the fire and lighting at him. They missed and he appeared behind them and grabbed them with his tendrils, once he got them, they use the powers to burn and shock Mōryōmaru, which surprised him. As both plan to damage Mōryōmaru from the inside, then all three of them started to fall as Byakuya watches. Once they hit ground, Mōryōmaru's tendrils release Ginka but didn't release Kinka, as soon as Ginka was freed, he attacked his brother and Mōryōmaru stabbed Ginka from the back with his Kongōsōha arm, killing the demon of lightning and devoured him (though Mōryōmaru devouring Ginka wasn't seen). Kinka, whose barley alive, saw his trick and try to attack him, then Mōryōmaru shot his Diamond Spears at him, killing him as well, which also allowed Mōryōmaru to consume Kinka, which made him stronger and allowed his Kongōsōha spears to be combined with powers of fire and lightning, much like how Inuyasha's Kongōsōha is also powered by his Kaze no Kizu.

Trivia

 * In the anime, Kinka served a similar role of battling with his brother, but the involvement of Inuyasha and his friends was removed, so Mōryōmaru had almost no problems taking Kinka's powers.
 * It is possible that Kinka is stronger than Ginka. As in both the anime and manga, Kinka survived slightly longer than his brother.