Hōsenki I

was an oyster-demon who cultivates a variety of magical jewels.

History
Hōsenki created the Black Pearl in Inuyasha's right eye that enabled Sesshōmaru to travel to his father's grave and try to steal Tessaiga, the sword his father willed to Inuyasha. When the Shikon no Tama was split into many shards, one came into Hosenki's possession as his life was coming to an end.

During the Story
Inuyasha's group needs to travel to the nether world and seek out Hōsenki, but learned he passed away and his son, who shares his name, can not make the gems yet. They found another path to the world where they find the departed Hōsenki sitting among the bone's of Inuyasha's father's body with the last shard of the jewel. Hosenki refused to give Inuyasha the shard. He said that the shard could speak to him, and that it did not want to merge with the rest of the jewel or else it would become corrupt. Hosenki soon became corrupt and by the evil of the Sacred jewel and attacked Inuyasha. After Naraku reclaimed his shard, Hōsenki returned to normal and allowed Inuyasha's Tessaiga's to learn his Kongōsōha attack.

Inuyasha was able to obtain the shard from Naraku after Kagome damaged Naraku's body. Hosenki allowed Inuyasha to keep the shard and warned him to leave before he would get trapped in the netherworld forever.

Powers & Abilities
Jewel Manipulation: Being an Oyster Daiyokai, Hōsenki possessed the ability to generate and manipulate gemstones and jewels to his liking with the most prominent being adamant, the hardest substance there is. Master Jewel Craftsman: Hōsenki possessed masterful skills in crafting jewels with special powers as he created the Black Pearl that was sealed into Inuyasha's right eye and possessed the power to open portals to the border of the Netherworld where the remains of the Inu no Taisho rests. Apparently crafting jewels of such power is an extraordinary skill all together even for a demon associated with gems as after his death, none of the Great Dog Demon's allies were able to obtain more Black Pearls with his son admitting that it would take him another 100 years to be able to create them as well thus showing great skills in this regard.
 * Kongōsōha: Hōsenki was the original wielder of this powerful technique. He was able to send a shower of adamant shards (diamonds) to injure his enemies. It is powerful enough to penetrate Naraku's stronger barrier and it is the only technique that is able to do so. It is also powerful enough to destroy large parts of the cliffs that surround the border between the living world and the afterlife.
 * Adamant Armor: Hōsenki was covered in adamant and because of that he had an incredible defense due to adamant being considered the strongest substance in the world. His defenses were able to withstand Inuyasha's Kaze no Kizu and repeated blows from Inuyasha's Tessaiga without much trouble. His defenses could still be breached, as they were by Naraku, because the corruption caused by his darkened shard had weakened him (Hōsenki) greatly.

Immense Demonic Power: Being a Daiyokai and a former ally of the Great Dog Demon himself, Hōsenki's power can be theorized to be comparable to Naraku's, as Naraku himself stated that, as long Hōsenki's shard was protected by both his adamant armor and demonic power, it was "even beyond my reach". It was only by corrupting the shard and manipulating Hōsenki into attacking Inuyasha that Naraku was able to weaken Hōsenki enough to allow his jewel shard to be stolen.

Immense Strength: He was strong enough to hit Inuyasha and send him flying. After the hit, Inuyasha lost consciousness for a short amount of time. Even after being weakened by both the corrupted shard and his internecine battle with Inuyasha, Hōsenki is still capable of ramming an adamant arm straight through both Naraku's previously unbreakable barrier and his body, though his defiance was in vain.

Allies
Hōsenki and Inuno Taishō were evidently great friends in life as Hōsenki agreed to arrange to make a black peral to allow Inuyasha to obtain Tessaiga while keeping it out of Sesshōmaru's hands. After Hōsenki died, his corpse took residence in the bones of the Inu no Taishō, a testament to how strong their friendship was even though the latter had been dead for over 200 years.
 * Inu no Taishō

Hōsenki Hozenki 宝仙鬼