「仮面ライダービルドBlu-ray COLLECTION」全4巻に収録。 全3話＋メイキング。 氷室幻徳 / ナイトローグ / 仮面ライダーローグを主役としたスピンオフ作品。 ファウストの誕生やテレビでも回想シーンで描かれている幻徳が東都を追放されていた間の話が描かれる。 時系列は、序章はテレビシリーズ第1話の3年前、第二章は第21話の真裏、最終章は第22話の真裏の話となっている。

After the end of the civil war that tore apart Japan, the new governors of Touto, Hokuto and Seito work together to reunify the country. However, they are actually members of an extraterrestrial race called the "Blood Tribe" (the same species as Evolto), who assumed their government positions as part of a plan to destroy Earth as they have done to Mars and other planets before. Considering Sento Kiryū (Kamen Rider Build) a major threat to their plans, the Blood Tribe manipulates his friends and other civilians into attacking him. With even his close ally Ryūga Banjō (Kamen Rider Cross-Z) now against him, Sento must fight to survive and stop the Blood Tribe's plan from succeeding.