This article is about a/an episode in Kamen Rider Build.
Red alert WARNING: This episode contains scenes of blood, bloodshed, and murder. Viewer discretion is advised!

Mad World (マッドな世界 Maddo na Sekai) is the thirty-eighth episode of Kamen Rider Build. It features the debut of Kamen Rider MadRogue and the Bat, Cobra, Shimauma and Hasami Lost Fullbottles, the deaths of Fu and Rai Washio and Juzaburo Namba, the former two of which will return 9 episodes later, and Utsumi's resulting insanity as well as Evolto's first on-screen transformation into Kamen Rider Evol Black Hole Form.


Finally, Evolto has transformed into his Phase 4 form, therefore completing his body! Cross-Z, Grease, and Rogue, three strong Riders are no match against his true form! Can they stop Evolto who has regained the ultimate power he used to destroy Mars? Meanwhile, Sento has recovered his memories as Katsuragi once again…


to be added


Guest Casts

Suit Actors

Forms and Collectibles Used


  • Bottle used:
    • Build
      • Biotic: FullFull RabbitTank (Rabbit Mode)
      • Abiotic: N/A
      • Other: Hazard Trigger
    • Cross-Z
    • Rogue
      • Biotic: Crocodile Crack
      • Abiotic: N/A
    • MadRogue
      • Biotic: Bat
      • Abiotic: Engine
  • Form used:
    • Build
      • RabbitRabbit Form
    • Cross-Z
      • Cross-Z Magma


  • Jelly used:
    • Grease
      • Robot


  • Bottle used:
  • Form used:
    • Evol
      • Black Hole Form (Phase 4: Perfection)
    • Cross-Z
      • Great Cross-Z


  • Gear used:
    • Engine Bro's
      • Gear Engine
    • Remocon Bro's
      • Gear Remocon
    • Hell Bro's
      • Gear Engine, Gear Remocon


Removed Touto Fullbottles

Fullbottles removed from Pandora Box in episode 36

Evolto's Fullbottles

Evolto's Fullbottles in this episode

  • In episode 36, the Pandora Box is shown in Sento's lab with the top Touto panel removed for Sento's research and the Rabbit, Tank, Taka, Gatling, Kaizoku, Densya, Panda, Rocket, Dragon, and Lock Fullbottles removed from said panel and placed on the table. When Banjo later presents the Pandora Box to Evolto, it is shown with the same panel and Fullbottles missing. However, in this episode, the remaining Touto panel on the Pandora Box contains the Fullbottles that were left in Sento's lab in the previous episode. These Fullbottles are later seen again in Evolto's briefcase.


Mad Rogue CS
  • Closing Screen Fullbottles:
    • Kamen Rider: MadRogue
    • Fullbottles:
      • Biotic: Bat
      • Abiotic: Engine
  • Count at episode end
    • Bottles in Build's possession: RabbitTank Sparkling, FullFull RabbitTank
    • Bottles in Cross-Z's possession:
    • Bottles in Grease's possession:
      • Biotic: Kuwagata, Fukurou
      • Abiotic: Castle
    • Bottles in Rogue's possession: Crocodile Crack
    • Bottles in Evol's possession:
      • Biotic: Rabbit, Gorilla, Taka, Ninjya, Panda, Harinezumi, Lion, Dragon, Kaizoku, Octopus, Phoenix, Wolf, Unicorn, Rose, Turtle, Kabutomushi, Kuma, Dog, Santa Claus, Spider, Tora, Kujira, Shika, Kirin, Penguin, Obake, Same, Hachi, Sai
      • Abiotic: Tank, Diamond, Gatling, Comic, Rocket, Syoubousya, Soujiki, Lock, Densya, Light, Robot, Smapho, Keshigomu, Helicopter, Watch, Camera, Televi, Mic, Cake, Reizoko, UFO, Jet, Pyramid, Senpuki, Sukebo, Magnet, Bike, Sensuikan, Dryer
    • Bottles in MadRogue's possession:
      • Biotic: Bat
      • Abiotic: Engine
    • Jellies in Grease's possession: Robot
    • Evolbottles in Cross-Z's possession:
    • Evolbottles in Evol's possession:
      • Biotic: Cobra, Rabbit
      • Abiotic: Rider
    • Lost Fullbottles in Evol's possession:
      • Biotic: Bat, Cobra, Shimauma
      • Abiotic: Hasami
  • This episode is the first episode since Rider Wars Start to not feature the opening credits, and the first since The Weaponry Hero where the opening theme is used at the end of the episode.
  • As Sento Kiryu narrates the opening narration, no other character made an attempt to interrupt him in anyway.
  • It is revealed that Katsuragi is unable to properly master Build's high-performance forms as shown when he assumed RabbitRabbit Form.
  • This is the first episode since it's debut that Kamen Rider Evol does not assume his Cobra Form.
  • Tragically, this episode would mark the final on-screen performance of suit actor Daichi Nobe, who passed away at the age of 21 on June 13, 2018, only ten days after its broadcast.[1]
  • This episode marks the 900th episode of the Heisei era Kamen Rider Series.
  • Utsumi exclaiming his loyalty for Evolto has become a running gag amongst the cast, as Eiji Akaso and Kouhei Takeda had each performed their own versions of the scene behind-the-scenes.

External links