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.

With Genta surviving a cell transfusion surgery, the Karizakis create the Giffard Rex Vistamp, which Ikki and Vice use to become Kamen Rider Ultimate Revice and give humanity hope and inspire citizens to either join Weekend in fighting Giff's tyranny or build shelters across the city. Furious, Akaishi begins his plot to invade Weekend's base. Meanwhile, Daiji leads a demon army to the resistance's base by forcing civilian's move to ARARAT and obey Giff orders, sparking a fierce conflict between Daiji and his siblings.