Kamen Rider Heisei Generations FINAL: Build & Ex-Aid with Legend Riders

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) is the Movie War (the ninth overall) crossover between Kamen Rider Build and Kamen Rider Ex-Aid, and the second installment of the Heisei Generations Series. The film premiered in Japanese theaters on December 9, 2017. It was followed by a teaser announcing the then-upcoming Kamen Rider Amazons: The Last Judgement.

The film was released on DVD/Blu-Ray on May 9, 2018.

Synopsis
The story begins following Ex-Aid and Para-DX's battle against Build during Power Rider Ex-Aid: True Ending. Build appeared and took Ex-Aid's powers away, but Sento has no recollection of such incident happening other than a dream. Misora has made two new Fullbottles.

When Rick Johnson arrived to a Smash distress call, he found a Nebula Bugster instead, the latest mutation of the Bugster Virus. While Sento battled the Nebula Buster, Ryuga was blown into an alternate reality where the Sky Wall never existed, where he meets Emu and the Gamer Riders. The Riders from the world of Build and the Riders from the world of Ex-Aid, alongside the Legend Riders Fourze, OOO, Gaim, and Ghost will stand up against this threat!

Plot
The film begins with Sento Kiryu dreaming about taking Ex-Aid's powers. When he wakes up after Misora finishes purifying the Doctor and Game Fullbottles, he tells the others about his weird dream and reveals his new RabbitTank Sparkling power-up bottle. Then, the team are called into battle when Nebula Bugsters begin attacking Touto. Realizing their powers have no effect on the monsters, Build accesses the Doctor and Game bottles for an Ex-Aid Best Match, then realizing that Ex-Aid was in his dream. Left Kaizer then appears and takes the new bottles from Build and runs off. Claws runs after him and gets sucked into Enigma, a inter-dimensional gateway that brought him to a parallel world where the Sky Wall never existed.

Nebula Bugsters begin to attack the public due to the interdimensional interference caused by Engima, alerting the attention of several former Kamen Riders. The Doctor Gamers arrive to the scene to try to calm the peace, with Emu out of commission due to Build taking his powers the week prior. Right Kaizer then appears and takes responsibility for unleashing the Nebula Bugsters for the sake of empowering the Enigma on his side. He activities the Enigma and sends Build's Earth to their dimension, with the denizens of each Earth in awe after seeing another Earth in the sky. Enigma activates again, this time it renders the Gamer Drivers and Gashats useless. Right Kaizer attacks the Riders, only for them to be protected by the appearance of Kamen Rider Ghost. Doctor Riders help quell the wounded civilians in medical care while Emu thanks Takeru and Onari for showing up. Then Ryuga appeared and began yelling at Asuna Karino about the Sky Wall. Emu notices the Build Driver on Ryuga and demands for his Ex-Aid powers back, with Ryuga dismissing the idea.

Meanwhile on Build's Earth, Parado has encountered Sento and demands for Emu's powers back, claiming it took him two entire years in an attempt to track Build down. After hearing Parado out, Sento realizes that Parado and "Ex-Aid" came from a world where the Sky Wall never existed. Soichi Isurugi appears and explains that Nebula Bugsters are monsters from a different world infused with their world's Nebula Gas, and the only one who can defeat them are "riders with the power of video games", which he tells Sento that that was the most likely reason as to why Sento refused to return Ex-Aid's bottles. He suggests that Parado use the Game Fullbottle to communicate with Emu on the other side, which succeeded. The conversation confirmed a time difference between the two worlds and that Enigma was able converge the two time zones into one linear flow, and to Sento's acknowledgement that Ryuga was on Ex-Aid's world. The Doctor Riders begin to work a plan out with Kuroto Dan, while Parado falls temporarily ill due to the influence of the Fullbottle over his virus physiology. Soichi continues to explain how Kaisei Mogami once found a way to cross over to parallel worlds using the Sky Wall, and tells Sento to stop him.

With a new plan in tow, Kuroto Dan faces the Nebula Bugsters with the new Kamen Rider Build Gashat he created from the data when Build attacked him. The new Gashat would allow him to temporarily conceal the lock embedded onto their gear, albeit only temporary. Kuroto is asked to make more, but he refuses until Onari successfully convinces him to do so.

Sento begins his investigating of Kaisei Mogami by retrieving a profile of him from Gentoku Himuro, to explains that Mogami worked very closely with Takumi Katsuragi.

Continuity and Placement

 * Kamen Rider Build: Between episodes 14 and 15. The event of this movie happens 2 years after Build's cameo in Kamen Rider Ex-Aid: True Ending in the world of Build's timeline.
 * Kamen Rider Ex-Aid: 1 week after Build's cameo in Kamen Rider Ex-Aid: True Ending in the world of Ex-Aid's timeline, but before Kamen Rider Ex-Aid "Tricks": Kamen Rider Para-DX.
 * Kamen Rider Ghost: After the events of Kamen Rider Ghost RE:BIRTH: Kamen Rider Specter.
 * Kamen Rider Gaim: After the events of the previous Heisei Generations movie.
 * Kamen Rider Fourze: Before the events of the Fourze portion of Kamen Rider × Kamen Rider Wizard & Fourze: Movie War Ultimatum.
 * Kamen Rider OOO: After the events of Kamen Rider × Kamen Rider Fourze & OOO: Movie War Mega Max, as well as Eiji's cameo in Kamen Rider × Kamen Rider Wizard & Fourze: Movie War Ultimatum.

Build

 * Misora Isurugi
 * Soichi Isurugi/Evolto
 * Sawa Takigawa
 * Gentoku Himuro

Ex-Aid

 * Parado
 * Asuna Karino
 * Nico Saiba

Others

 * Onari Yamanouchi
 * JK
 * Chuta Ohsugi

Bugster

 * Nebula Bugster

Cast

 * Build cast
 * Sento Kiryu (桐生 戦兎): Atsuhiro Inukai (犬飼 貴丈)
 * Ryuga Banjou (万丈 龍我): Eiji Akaso (赤楚 衛二)
 * Misora Isurugi (石動 美空): Kaho Takada (高田 夏帆)
 * Sawa Takigawa (滝川 紗羽): Yukari Taki (滝 裕可里)
 * Gentoku Himuro (氷室 幻徳): Kensei Mikami (水上 剣星)
 * Soichi Isurugi (石動 惣一): Yasuyuki Maekawa (前川 泰之)
 * Ex-Aid cast
 * Emu Hojo (宝生 永夢): Hiroki Iijima (飯島 寛騎)
 * Hiiro Kagami (鏡 飛彩): Toshiki Seto (瀬戸 利樹)
 * Taiga Hanaya (花家 大我): Ukyo Matsumoto (松本 享恭)
 * Kuroto Dan (檀 黎斗): Tetsuya Iwanaga (岩永 徹也)
 * Asuna Karino (仮野 明日那): Ruka Matsuda (松田 るか)
 * Kiriya Kujo (九条 貴利矢): Hayato Onozuka (小野塚 勇人)
 * Parado (パラド): Shouma Kai (甲斐 翔真)
 * Nico Saiba (西馬 ニコ): Reina Kurosaki (黒崎 レイナ)
 * Returning cast
 * Eiji Hino (火野 映司): Shu Watanabe (渡部 秀)
 * Ankh (アンク): Ryosuke Miura (三浦 涼介)
 * Gentaro Kisaragi (如月 弦太朗): Sota Fukushi (福士 蒼汰)
 * JK (ジェイク): Shion Tsuchiya (土屋 シオン)
 * Chuta Ohsugi (大杉 忠太): Takushi Tanaka (田中 卓志)
 * Kouta Kazuraba (葛葉 紘汰): Gaku Sano (佐野 岳)
 * Takeru Tenkuji (天空寺 タケル): Shun Nishime (西銘 駿)
 * Onari Yamanouchi (山ノ内 御成): Takayuki Yanagi (柳 喬之)
 * Musashi Damashii, Nobunaga Damashii, Grimm Damashii (ムサシ魂, ノブナガ魂, グリム魂): Tomokazu Seki (関 智一)
 * Guest Cast
 * Kaisei Mogami (最上魁星): Kenji Ohtsuki (大槻 ケンヂ)

Uncredited

 * Kamen Rider Grease (仮面ライダーグリス): Kouhei Takeda (武田 航平)

Suit Actors

 * Kamen Rider Build, Kamen Rider OOO, Kamen Rider Fourze, Kamen Rider Gaim: Seiji Takaiwa (高岩 成二)
 * Kamen Rider Ex-Aid: Yuji Nakata (中田 裕士)
 * Kamen Rider Cross-Z: Eitoku (永徳)
 * Kamen Rider Grease: Satoshi Fujita (藤田 慧)

Fullbottles

 * Bottle Used:
 * Build
 * Organic: Rabbit, Doctor, Kaizoku, Lion (in Build Phone), Taka, Ninjya, Phoenix
 * Inorganic: Tank, Game, Densha, Gatling, Comic, Robot
 * Other: RabbitTank Sparkling
 * Cross-Z
 * Dragon
 * Form Used:
 * Build
 * RabbitTank Form, Ex-Aid Form, KaizokuRessya Form, HawkGatling Form, NinninComic Form, PhoenixRobo Form, RabbitTank Sparkling Form

Rider Gashat

 * Gashat Used:
 * Ex-Aid
 * Mighty Action X, Maximum Mighty X, Hyper Muteki, Bakusou Bike (in Kimewaza Slot Holder), Kamen Rider Build (in Gashacon Breaker)
 * Brave
 * Taddle Legacy, Taddle Quest, Kamen Rider Build
 * Snipe
 * Gashat Gear Dual β (Bang Bang Simulations), Bang Bang Shooting, Kamen Rider Build
 * Lazer (Turbo)
 * Bakusou Bike, Kamen Rider Build
 * Genm
 * Gamer Driver
 * Dangerous Zombie, Kamen Rider Build
 * Level Used:
 * Ex-Aid
 * Action Gamer Level 2, Muteki Gamer
 * Brave
 * Legacy Gamer Level 100, Quest Gamer Level 2
 * Snipe
 * Simulation Gamer Level 50, Shooting Gamer Level 2
 * Lazer (Turbo)
 * Bike Gamer Level 2, Bike Gamer Level 0
 * Genm
 * Zombie Action Gamer Level X-0

Ghost Eyecons

 * Eyecon Used:
 * Ore, Newton, Eyecon Driver G, Mugen
 * Damashii Used:
 * Ore Damashii, Newton Damashii, Grateful Damashii, Mugen Damashii
 * Ghosts summoned through Eyecon Driver G:
 * Musashi, Nobunaga, Houdini, Grimm

Lockseeds

 * Lock Used:
 * Orange, Sakura Hurricane, Kachidoki, Kiwami
 * Arms Changes
 * Orange Arms, Kachidoki Arms, Kiwami Arms
 * Lock Vehicle:
 * Sakura Hurricane

Astroswitches

 * Switches Used:
 * Circle - Rocket, Chain Array, Cosmic
 * Cross - Giantfoot, Launcher
 * Triangle - Gatling, Drill
 * Square - N/A
 * States Used:
 * Base States, Cosmic States

Core Medals

 * Medals Used:
 * Head - Taka, Kuwagata
 * Arms - Tora, Kamakiri, Kujaku
 * Legs - Batta, Condor
 * Combos Used:
 * Tatoba Combo, Gatakiriba Combo, Tajadol Combo

Theme song

 * Kamen Rider Heisei Generations FINAL Special Medley

International Movie Theaters
The film was released in Taiwan in February 2018, and Hong Kong in March 2018, available in both Japanese language with Chinese subtitles and Chinese dub.

Errors

 * When the Doctor Riders activate Kamen Rider Build Gashats to transform, they don't wear a Gamer Driver, but it suddenly appears in the very next scene.
 * When Emu transforms and the profile array appears, two silhouettes are seen in place of Ex-Aid's Double Action Gamer Level X and Genm's Action Gamer Level 1, even though they aren't seen when the other Doctor Rider transform.
 * When Emu transforms, Bike Gamer is also materialized, even though he didn't activate a Bakusou Bike Gashat.
 * Before Takeru transforms into Ghost, he is not seen summoning the Ghost Driver and it just appears on him even though it wasn't there in the previous scene.
 * On one scene, the Build suit is actually reversed while Ex-Aid Muteki Gamer is fighting Bi-Kaiser.
 * When Fourze performs the Rider Rocket Drill Kick in his Cosmic States, it is impossible to use any switches on the right arm.