|Affiliation|| Lord Mei-Oh (former)|
Lord Toda (former)
Burning Dawn (former)
Cave bandits (former)
Manji cult (former)
|Weapon|| Chinese Jian (former)|
|Status||Unknown, possibly possessing Ayame|
|First Appearance||Tenchu: Stealth Assassins|
Onikage has been involved in a personal feud with the House of Gohda for generations, and is a primary antagonist of Gohda's retainers, the Azuma ninjitsu clan. Onikage now exists only to torment Gohda and the leader of the Azuma, Rikimaru.
Onikage's origins are mysterious, but dialogue in various games would suggest that he was once a mortal shinobi who became undead through supernatural and dark powers. Onikage both worships and serves the demonic overlord Mei-Oh and is his representative in the mortal realm.
It is Mei-Oh (or in one case, Tenrai) who has frequently resurrected Onikage from the dead, and with Onikage becoming less human and more demonic in appearance each time. Onikage shows sadomasochistic tendencies, delighting in the torment and death of others, but also in his own deaths. This is why he eventually gives up using weaponry altogether, relying mostly on leg-based melee combat, since he has a strength far beyond of ordinary human.
Onikage was once a ninja that went by the name of Suzaku (朱雀), the Red Sparrow. He pretended to be blind by wearing a black blindfold, and provided counsel and advice to Lady Kagami as one of the Four Lords of the Burning Dawn. He murdered his lover, Yukihotaru, after she was defeated by Rikimaru at the Buddhist Temple, stating that he had "no love for weakness, only power."
Later Rikimaru defeated him in a second large ship during the final battle, before he fought against Lady Kagami. Both were slain by Rikimaru with Izayoi, who had recently come to be head of the Azuma clan in stead of the traitorous Tatsumaru, who had also been seduced by the Red Sparrow and Kagami. In the Red Sparrow's death scene, he mocks Rikimaru, saying that it is his destiny to become just like him; Rikimaru rebukes this, saying that he won't since he serves a worthy master. After dying, the Red Sparrow is seen rising from the dead amid the surrounding corpses and flames, and removing his disguise to reveal that he is a jubilant Onikage.
After abandoning the guise of the Red Sparrow, Onikage reappeared many years later to create chaos and prepare for Mei-Oh in coming to Earth. Onikage arranged with some bandits for the capture of one of the Azuma ninja; was behind the Manji cult; decimated one of Godha's castles; and kidnapped Princess Kiku. Rikimaru fought him numerous times, unaware that Onikage and Suzaku were the same person. Onikage never revealed his former identity to him for unknown reasons. Rikimaru killed both Onikage and Mei-Oh, sent back to their own realm by Izayoi.
Onikage was brought back to life by a sorcerer named Tenrai. He then served him while secretly making plans to bring back his true master, Mei-Oh. After Rikimaru killed Tenrai, Onikage informed the spirit of Mei-Oh that his time to return was at hand.
Three years later, Onikage returns and assumes the identity of Naotada Sekiya, Lord Gohda's longtime advisor. Assisted by a woman named Rinshi, they begin an elaborate plot to lead the clan into thinking a war is brewing. This eventually leads to Rikimaru being marked as traitor. He seized the castle and burned it while Rikimaru and Ayame were led to different places. In the extended ending to the game, Onikage is apparently victorious having possessed Ayame.
Onikage calls upon the forces of darkness, granting him many arcane abilities. In Tenchu: Stealth Assassins, and Tenchu: Wrath of Heaven, he fights bare-handed, using fast and powerful Tae Kwon Do-like kicks. As the Red Sparrow in Birth of the Stealth Assassins, he uses the same Tae Kwon Do style combined to a chinese Jian sword.
- His name means Demon Shadow Oni (Demon) Kage (Shadow), which makes sense considering he served under Lord Mei-Oh.
- In the original Tenchu game, the player can make Onikage a playable character by entering the debug mode, spawning Onikage, and changing the player's POV to that of Onikage. Although only his roundhouse and flying kicks are initially available to attack with, Onikage can still use any items picked up.
- Onikage is one of the playable characters featured in the two player versus mode of Tenchu: Wrath of Heaven.
- Onikage has on occasion displayed a strange attraction to Ayame, once saying that she is exemplary mortal, and that a death by her is "a beautiful death". The last we see of them so far (in the extended ending to Tenchu 4), Onikage is apparently possessing Ayame.