Ryūra

was a fierce warrior and the leader of the demon band known as the Four War Gods (Shitōshin). Many years ago, Ryūra and his comrades invaded the legendary island Hōraijima and caused much distruction. In desperation, the island's priestess, Lady Kanade, sealed the Four War Gods' spheres of power inside a jeweled comb box and hid it inside the Cauldron of Resonance. Without their powers, the Four War Gods were forced to remain on the island until they could retrieve the comb box.

Eventually, the Four War Gods initiated a plan that would allow them to regain their original power by using a cloned priestess. During the course of executing this plan, however, the Four War Gods were opposed by many opponents, among them the half-demon Inuyasha.

History
Ryura and his brothers originally came with a army of demons(though they were not the leaders of the army merely just part of the group) it's not said what happened to the other demons though the four war gods had their powers stolen and sealed they soon began to sacrifice half demons to regain bits of their power at a time.

Personality
Ryura is extrememly arrogant and sadistic he also seems to seek out strong opponents to face in battle.

Trivia

 * Ryūra is one of the four antagonists created for InuYasha the Movie: Fire on the Mystic Island. Each of the Four War Gods is based on one of the Four Sacred Animals of Chinese mythology and astronomy, a common motif in anime and manga. Of the four animals/constellations that make up the group, Ryūra represents the Azure Dragon of the East known in Japanese as Seiryū. The dragon arm formations on his shoulders, his ability to manipulate the weather, and the shape of the energy discharged by his power sphere upon his death, all reflect this.
 * Coincidentally, Seiryū is one of the demon ninjas under Hoshiyomi. Each of these four ninjas have, like the Four War Gods, an affiliation with one of the Four Sacred Animals. Seiryū has many reptilian features and mannerisms which signify his affiliation with the Azure Dragon, besides his name. However, he appears to be more snake or lizard-like, and has no obvious connections with a dragon, unlike Ryūra.
 * Similar to Menōmaru, the style of dressed employed by the three humanoid members of the Shitōshin is very Chinese in appearance, and does not reflect any Japanese influences. This reflects the Chinese origins of the Hōrai Island myth, known in China as Mount Penglai.
 * Ryūra's Japanese seiyū also provides the voice for Hiten, the eldest of the Thunder Brothers. It is worth noting that both characters have long, braided ponytails, red eyes, and use lightning-based attacks.