The Igarashi siblings, George, and Weekend must recoordinate their plan to save Akemi, who has fallen into darkness, and prevent Akaishi from announcing his plan to bring about a demon apocalypse on Earth. As the heroes' situation worsens when Akaishi, Giff, and Vail decimate a majority of Fenix's forces, Hikaru is able to convince George to grant the former an upgraded Demons Driver and the Kuwagata Vistamp that the latter developed to transform into Kamen Rider Over Demons before retreating with their allies back to Weekend.

In response to Giff's full scale invasion of Earth and Fenix's failed demon removal stamps, Weekend publicly reveals themselves to the world and urges civilians to rebel against Akaishi and his lies, despite the risk. Meanwhile, as they are working on a solution to free Akemi from her Giffdemos form, Daiji becomes concerned about his ability to protect world peace. While George upgrades the Barix Rex Vistamp to allow Vice to transform into a similar version of Ikki's Barid Rex Genome, Ikki recalls that Akemi's will remains intact and she potentially left a clue to defeat Giff.