Kyōra

Kyōra (凶羅, Evil Mist) was a powerful demon and one of the four members of the Four War Gods (Shitōshin). Many years ago, he and his comrades invaded the island of Hōraijima and devastated the population. Unable to defeat the Four War Gods, the island's priestess, Lady Kanade, sealed their power spheres inside a jeweled comb box. Unable to leave the island without their powers, the Four War Gods established themselves on Hōraijima.

The Four War Gods initiated a plan to regain their former power and escape from the island. However, they were opposed by many enemies, amongst them Lord Sesshōmaru. Having fought Sesshōmaru in the past, Kyōra was eager to face off with his nemesis once again. However, this would prove to be a fatal last encounter.

Invasion of Hōraijima
Many ages ago, the island of Hōraijima was a sanctuary for humans and demons alike. The two groups existed in harmony for many years and intermingled, giving rise to a sizeable population of half-demons. The existence of a half-demon community earned contempt from demons, so, to protect themselves, the people of Hōraijima created the powerful Cauldron of Resonance, which generated a time barrier that separated Hōraijima from the outside world. However, every 50 years the time barrier weakened, and the island reappeared, rendering it vulnerable to raids by demons. The Four War Gods were among the many demons which despised the people of Hōraijima, and one day decided to attack the island during its brief vulnerable period and annihilate its inhabitants.

The humans and demons of Hōraijima were no match for the Four War Gods, among whom was the demon Kyōra. The village became engulfed in flame and many villagers fell in battle. However, Kyōra and the other War Gods had neglected to kill the island priestess, Kanade. Lady Kanade was quite powerful, but not even she could defeat the combined power of the Four War Gods. In desperation, Lady Kanade was able to seal away the power spheres which granted the four demons their immense power inside a jeweled comb box. With this accomplished, Kanade lept inside the Cauldron of Resonance, putting the box beyond the reach of any of the Four War Gods. With the island already conquered, Kyōra and the others established themselves temporarily on Hōraijima, until they could find a solution to their missing powers.

In time, the Four War Gods discovered that by throwing live half-demons into the Cauldron of Resonance, they could retrieve a portion of their powers trapped inside. In order to survive, the War Gods put their mark on each of the island's half-demons and established a powerful demonic barrier around the island. Anyone who carried the mark would be unable to pass outside the barrier. In this way, the Four War Gods were able to keep the half-demons enslaved, sacrificing them one by one whenever their powers needed rejuvenation. Nevertheless, this was a temporary solution at best, since the War Gods could never retrieve their full powers; furthermore, if they left the island, they would slowly fade away from a lack of demonic energy and die. In order to stay alive, the Four War Gods would have to remain on the island, where they could retain access to the Cauldron. Also, due to the slowing effect of the time barrier, the Four War Gods could minimize the amount of power they lost, meaning that they would only need to sacrifice a half-demon whenever the barrier itself weakened (e.g. every 50 years). But until they could retrieve the jeweled comb box from within the Cauldron, the Shitōshin would be trapped on the island forever.