Rider War (Kamen Rider Taisen)

A Rider War (ライダー大戦) between the Heisei Riders and Showa Riders occured across the cities of Zawame and Futo during the rise of the Underground Empire Badan. Though Badan had appeared to take advantage of the divide, it was ultimately revealed that the Kamen Riders were infact playing them as they returned from defeat to unite and take down the Underground Empire Badan. After Badan was defeated, the fifteen Heisei Riders and fifteen Showa Riders faced each other in a clash which ended in the reconciliation of the two sides' differences.

This Rider War was refered to as such by.