|This article is about a/an event in Kamen Rider Ryuki.|
The battle itself was discovered and used by Yui's older brother, Shiro Kanzaki. Although the victor is awarded the wish, Shiro manipulated the war for his own. In actuality, Shiro plans to become the victor so that he could wish for Yui's well-being.
He constantly intervenes with the fights through his puppet Rider, Kamen Rider Odin would gain an upper hand. Although the power of his puppet was said to surpass the others, Ryuki and Knight have always miraculously overpowered them.
Despite countless attempts at manipulating the results of the war by Shiro to ensure victory for Odin, ultimately Knight stands as the last survivor and winner of Rider Fight, last beating Odin after Odin fades away thanks to Yui successfully convincing Shiro to stop the destructive course of his actions.
World of Ryuki
In the alternate reality World of Ryuki, instead of the Rider War, there is the Kamen Rider Trial (仮面ライダー裁判 Kamen Raidā Saiban), a battle where the Kamen Riders fight each other within the Mirror World alongside their Contract Monsters in order for the victor to decide the fate of a defendant in a criminal case. Though no harm occurs to the Rider while in the Mirror World, a battle in the real world can be fatal and use of Vent cards outside a battle is forbidden.
Kamen Rider Zi-O
16 years later, a woman named Sara had her mirror counterpart announce the Rider Fight once more, in order to stop her boyfriend killing people as Another Ryuki. The only things different with the rule is the fight got limited to seven days. On the Fifth day, however, due to Sara Worsening condition, Sara reduce the limit into One day, resulting in the battle lasting for a total of six days. Ultimately, Shinji Kido becomes the winner of this battle and Sara return Shinji to Real World with her life as the cost.
|Ryuki||Koichi Sakakibara ► Shinji Kido|
|Knight||Ren Akiyama ► Shinji Kido (alternate timeline)|
|Scissors||Masashi Sudo ► Ishihashi|
|Zolda||Shuichi Kitaoka ► Goro Yura|
|Raia||Yuichi Saito ► Miyuki Tezuka|
|Odin||First Odin ► Second Odin ► Third Odin ► Unnamed man|
|Tiger||Satoru Tojo ► Tozuka|
|Imperer||Mitsuru Sano ► Ishida|
|Verde||Itsuro Takamizawa ► Kimura|
|Alternative Zero||Hideyuki Kagawa|
- It seems that the wish cannot revive the deceased, as shown when Ren fights to wake up Eri before she dies and Shiro Kanzaki orchestrates the entire war to make sure Yui gets a new life before her twentieth birthday. This is somewhat contradicted by Episode Final and the SIC series, though in the former has Miho preserve her sister's body in ice to make sure she revives.
- Even though Shiro only grants the wish of the winner of Rider Fight, in the end three Riders (Knight, Ryuki, and Raia) would have their wishes granted by Shiro. Knight had his wish (brought Eri back from coma) granted once he's declared the winner, whilst Ryuki and Raia's wishes (stop the Rider Fight) were unintentionally granted when Shiro used the power of Time Vent for the last time to stop the Fight from happening in the first place.