Kamen Rider Heisei Generations Final: Build & Ex-Aid with Legend Riders (仮面ライダー平成ジェネレーションズFINAL ビルド＆エグゼイドwithレジェンドライダー, Kamen Raidā Heisei Jenerēshonzu Fainaru: Birudo ando Eguzeido wizu Rejendo Raidā) is a Japanese superhero crossover film between Kamen Rider Build and Kamen Rider Ex-Aid, serving as the 9th Movie War and the second installment of the Generations Series. The film features supporting roles from OOO, Fourze, Gaim, and Ghost as they race against time to help Ex-Aid and Build stop a mad scientist from destroying their worlds. Kamen Rider Grease makes an early-bird appearance ahead of his in-series debut. The catchphrase for this film is "The strongest heroes gather! In the face of the evil scientist's plan to exterminate humanity, 6 warriors will stand up and fight." (最強ヒーロー集結 凶悪科学者の人類消滅計画に、6人の戦士が立ち上がる。, Saikyō hīrō shūketsu Kyōaku kagaku-sha no jinrui shōmetsu keikaku ni, 6-nin no senshi ga tachiagaru.)