OVA
Description
Soki, born Ogimaru Tokugawa in 1574, was the illegitimate second son of Ieyasu Tokugawa and Lady Oman. Inheriting Oni blood from his mother, he manifested the rare traits of the Black Oni, the reincarnated God of Darkness. Lady Oman gifted him the broadsword Lamentation during his early childhood before her unexplained disappearance; another blade, Requiem, was likely also provided by her. Initially designated heir to the Tokugawa clan following his elder half-brother Nobuyasu's forced suicide, he became a political hostage to Hideyoshi Toyotomi as part of a peace agreement. This led to his adoption and renaming as Hideyasu Hashiba. A formative three-year residence in Osaka Castle saw him bond with Ohatsu, who harbored deep affection for him, and develop animosity toward Mitsunari Ishida.
A pivotal trauma occurred during Hideyoshi's 1587 Kyushu campaign, where Hideyasu witnessed soldiers committing atrocities—decapitating civilians and preserving ears as trophies—including the murder of Roberto Frois' mother. This experience led him to renounce violence entirely. Following the 1589 birth of Hideyoshi's biological heir Hideyori and his subsequent adoption by Harutomo Yuki in 1590, he assumed the name Hideyasu Yuki. Despite becoming head of the Yuki household, he resented his obligations and plotted to abandon this life. His disillusionment with Hideyoshi intensified in 1596 after the mass execution of Hidetsugu Toyotomi's family.
In 1597, during a confrontation at Fushimi Castle, Hideyasu publicly denounced Hideyoshi's alliance with the Genma and his use of Genma Trees—structures grown from human bodies to produce mind-controlling insects. He attempted to assassinate Hideyoshi but was thwarted by Kiyomasa Kato, who consumed Genma Insects to gain superhuman strength. Amid an earthquake signaling the Omen Star's emergence, Hideyasu's rage unconsciously awakened his Oni powers. Heeding a telepathic command from Tenkai Nankobo to retreat, he escaped and replaced himself with his identical twin brother Sada-ai to assume lordship duties, freeing himself to oppose Hideyoshi.
Adopting the alias "Soki" to symbolize his break from Hideyasu, he embarked on a campaign to destroy Genma Trees across Japan. His actions—burning the trees and effortlessly slaughtering Genma forces—earned him the epithets "Blue Demon" for his azure armor and "Oni of the Ash" for the embers left in his wake. Minokichi, a Mino clan member, aided him by providing transportation, intelligence, and tactical support. During this crusade, Soki allied with Akane Yagyu, inheritor of the Jubei name and wielder of a Demon Eye; Ohatsu, now grappling with her sister Lady Yodo's corruption; Roberto Frois, a Spanish missionary seeking vengeance against his Genma-corrupted guardian; and Tenkai Nankobo, later revealed as the aged Samanosuke Akechi.
Tenkai recognized Soki as the Black Oni and guided him to Mt. Hiei, where Soki underwent trials by the tengu Arin to master his Oni abilities. This transformation allowed him to temporarily enter an empowered Oni state. The group confronted Hideyoshi and the Genma Triumvirate—Claudius, Rosencrantz, and Ophelia—uncovering Hideyoshi's role as a puppet for resurrecting the Genma deity Fortinbras. After Minokichi sacrificed himself to ensure the group's advance and Hideyoshi's defeat, Munenori Yagyu seized the Genma Seed to fully resurrect Fortinbras. Tenkai surrendered his Oni Gauntlet, containing a Genma Lord's soul, to Soki. Soki then channeled both his Oni essence and the gauntlet's power to destroy Fortinbras, an act that consumed his life force. His final moments included reconciling with his dying father Hideyoshi and enabling peace to return to Japan.
Soki wielded broadswords and katanas with exceptional proficiency, favoring Lamentation and Requiem. His combat style blended brute force with precision, often employing dual blades. As the Black Oni, he could absorb souls to heal or enhance his weapons and armor. His character arc transitioned from an idealistic youth scarred by war to a determined revolutionary, culminating in a self-sacrifice that balanced his inherited darkness with a commitment to humanity's protection.
A pivotal trauma occurred during Hideyoshi's 1587 Kyushu campaign, where Hideyasu witnessed soldiers committing atrocities—decapitating civilians and preserving ears as trophies—including the murder of Roberto Frois' mother. This experience led him to renounce violence entirely. Following the 1589 birth of Hideyoshi's biological heir Hideyori and his subsequent adoption by Harutomo Yuki in 1590, he assumed the name Hideyasu Yuki. Despite becoming head of the Yuki household, he resented his obligations and plotted to abandon this life. His disillusionment with Hideyoshi intensified in 1596 after the mass execution of Hidetsugu Toyotomi's family.
In 1597, during a confrontation at Fushimi Castle, Hideyasu publicly denounced Hideyoshi's alliance with the Genma and his use of Genma Trees—structures grown from human bodies to produce mind-controlling insects. He attempted to assassinate Hideyoshi but was thwarted by Kiyomasa Kato, who consumed Genma Insects to gain superhuman strength. Amid an earthquake signaling the Omen Star's emergence, Hideyasu's rage unconsciously awakened his Oni powers. Heeding a telepathic command from Tenkai Nankobo to retreat, he escaped and replaced himself with his identical twin brother Sada-ai to assume lordship duties, freeing himself to oppose Hideyoshi.
Adopting the alias "Soki" to symbolize his break from Hideyasu, he embarked on a campaign to destroy Genma Trees across Japan. His actions—burning the trees and effortlessly slaughtering Genma forces—earned him the epithets "Blue Demon" for his azure armor and "Oni of the Ash" for the embers left in his wake. Minokichi, a Mino clan member, aided him by providing transportation, intelligence, and tactical support. During this crusade, Soki allied with Akane Yagyu, inheritor of the Jubei name and wielder of a Demon Eye; Ohatsu, now grappling with her sister Lady Yodo's corruption; Roberto Frois, a Spanish missionary seeking vengeance against his Genma-corrupted guardian; and Tenkai Nankobo, later revealed as the aged Samanosuke Akechi.
Tenkai recognized Soki as the Black Oni and guided him to Mt. Hiei, where Soki underwent trials by the tengu Arin to master his Oni abilities. This transformation allowed him to temporarily enter an empowered Oni state. The group confronted Hideyoshi and the Genma Triumvirate—Claudius, Rosencrantz, and Ophelia—uncovering Hideyoshi's role as a puppet for resurrecting the Genma deity Fortinbras. After Minokichi sacrificed himself to ensure the group's advance and Hideyoshi's defeat, Munenori Yagyu seized the Genma Seed to fully resurrect Fortinbras. Tenkai surrendered his Oni Gauntlet, containing a Genma Lord's soul, to Soki. Soki then channeled both his Oni essence and the gauntlet's power to destroy Fortinbras, an act that consumed his life force. His final moments included reconciling with his dying father Hideyoshi and enabling peace to return to Japan.
Soki wielded broadswords and katanas with exceptional proficiency, favoring Lamentation and Requiem. His combat style blended brute force with precision, often employing dual blades. As the Black Oni, he could absorb souls to heal or enhance his weapons and armor. His character arc transitioned from an idealistic youth scarred by war to a determined revolutionary, culminating in a self-sacrifice that balanced his inherited darkness with a commitment to humanity's protection.