Yuji Kiba/Paradise Lost

In an alternate story where Smart Brain and the Orphnochs won, Yuji Kiba (木場 勇治) was a young man who became the Horse Orphnoch (ホースオルフェノク) who was friends with Takumi Inui. Following the deaths of his Orphnoch friends and the supposed "betrayal" of Mari Sonoda, Kiba briefly turns on humanity and used one of the Emperor Belts, becoming Kamen Rider Orga (仮面ライダーオーガ).

Paradise Lost
In the film, Kiba was the primary user of the Orga Gear. In the events of the film, Yuji Kiba is brainwashed by the Smart Brain corporation and is chosen to be the user of the Orga Gear, allowing him to transform into Kamen Rider Orga. The Orga gear was recorded as the fifth Rider Gear created by Smart Brain, after the Faiz and Kaixa Gears were stolen by the humans and the Riotrooper gear had undergone mass-production. Created alongside the Psyga Gear, the Orga Gear is regarded as a "perfect" gear, and therefore it can only be worn by Orphnochs. Kamen Rider Orga has a more ornate appearance than any of the previous Gears, the Rider form having robes made of Soul Foam for a majestic appearance. Orga is armed with the Orga Stlanzer sword which he uses in the Orga Slash Extreme Charge. He is sent to fight Kamen Rider Faiz after Psyga is defeated. Faiz is finally able to defeat Kamen Rider Orga with Blaster Forms Rider Kick, but does not kill him. Instead, Orga dies while trying to hold off the Elasmotherium Orphnoch so Faiz can destroy it, after Takumi finally gets through to him and reminds him of what Smart Brain really stands for and what his true values are.

Type22. - A Man's Lucky Food is Oden!
Kamen Rider Orga appears with Decade Complete Form, Exceed Gills and Chalice Wild Form, according by Momotaros. Orga is considered a devilish Rider.

Type39. - Ice Pop! Your White Self Matures Later!
Kamen Rider Orga appears with Zolda, Garren and Double LunaTrigger,according by Momotaros Orga again is considered an devilish Rider.

All Kamen Rider: Rider Revolution
Yuji Kiba as Horse Orphnoch and Orga, appeared as an unlockable character in this game. His Rider Ability is Dash Form and his Finisher is transform into Orga and executes Orga Stlash.

Battle Spirits
Horse Orphnoch appears with other Kamen Riders and Monters in Battle Spirits.

Kamen Rider Battle: Ganbaride
Kamen Rider Orga and Horse Orphnoch as support characters appeared in Kamen Rider Battle Ganbaride.

Kamen Rider Battle Rush
Kamen Rider Orga and Horse Orphnoch appears as a playable and support character in the video game Kamen Rider Battle Rush using Orga Stlash.

Kamen Rider Buttobasoul
Kamen Rider Orga is a playable character in Kamen Rider Buttobasoul.

As Kamen Rider Orga

 * SB-000B Orga Driver - Orga's transformation device.
 * SB-000P Orga Phone - The control unit of Orga Gear.
 * Orga Mission Memory - A small metallic card key containing the information of the Orga Armor.
 * SB-000S Orga Stlanzer - Orga's main sword weapon.

Rider Cards

 * Kamen Ride: Orga: A Rider Card containing the power of Kamen Rider Orga, possessed by Kamen Rider Diend. It one of the eight cards used by Diend Complete Form. It summons Kamen Rider Orga.
 * Attack Ride: Gekijyouban: Summons the eight Riders that make up Diend Complete Form. "Gekijouban" translates to "Movie Version" (劇場版), as movie riders are used in the attack. It is similar to Decade's Televikun card.

Portrayal
Yuji Kiba was portrayed by the late Masayuki Izumi (泉 政行).