- Written By: Shogo MutoDirected By: Takayuki Shibasaki
Sento: In order to take over the nation, the extraterrestrial entity Evolt has begun gathering 10 Lost Bottles, extracted from ten powerful monsters, the Lost Smashes. Kamen Rider Build AKA Kiryuu Sento is searching for his father, Shinobu, creator of the bottles...
Misora: Gentoku! Why do you keep choosing clothes like that?!
Gentoku: Why can't you accept my amazing fashion sense?
Kazumi: Miitan, can you help me coordinate my outfits?
Sawa: Kazumin, if you want Miitan's help, that'll be a million dollarks.
Ryuga: Man, I'm starved! Time for some protein!
Sento: And that's enough of that. Look, things have been going crazy while you guys were occupied. So pay attention, before we get into Episode 42.
Sento’s father, Shinobu Katsuragi, is alive and is working alongside Evolt! This information is starting to greatly worry the Build team, as it seems that Shinobu’s mission is to collect all of the Lost Bottles and add them to the black Pandora Panel and there is the possibility that Shinobu could be the one who is pulling the strings. Sento believes in the righteous purpose of the system that his father developed, but in midst of the action, another Build appears.
Episode Tropes:
- The Berserker: Something inside Ryuga snapped after having another flashback of Mars' destruction, causing him to let loose onto Mad Rogue, and then tries to take his frustrations out on a downed Hard Guardian once Utsumi escapes.
- Curb-Stomp Battle: Two examples:
- Ryuga doles one out to Utsumi after witnessing Evolt's Black Hole Finish from the bridge, moving faster and hitting harder than he has ever done before as Cross-Z Magma.
- The second Build causes a Smoke Out with NinninComic and ambushes Ryuga and Kazumi. Once the smoke clears, Ryuga, as his only target, falls over in pain and forced out of his transformation with the second Build already gone before he could be noticed.
- Dramatic Unmask: After Sento and Gentoku defeat Utsumi, the second Build appears before them and dismisses his transformation, revealing himself to be Shinobu Katsuragi, Sento's father.
- Early-Bird Cameo: When Ryuga reclaims the Dragon FullBottle, it turns silver, and come the closing screens, a gold Rabbit FullBottle is next to it. Both will become important come the summer movie.
- Hero with Bad Publicity: Evolt decides to organize the masses by delivering a speech as Mido to convince them that the Japanese Civil War is over, and then later spreads news about the Kamen Riders being anti-government insurrectionists using himself and Utsumi in their transformed state to discredit the Kamen Riders.
- Heroic BSoD: Gentoku has one when he sees Evolt destroy the Touto Residence Building with a black hole, as it was the last remaining icon of his deceased father's embassy.
- Heroic Second Wind. Both Sento and Gentoku have one after getting their butts kicked by Mad Rogue in the last third of the episode.
- "Not So Different" Remark: Both Sento and Gentoku realize that they have something in common: Both want to uphold their father's promises (Gentoku's promise to lead Touto, and Sento's promise to take down Evolt), but neither of them have succeeded yet.
- Wham Shot:
- Not only is there another Kamen Rider Build, but his identity is Shinobu Katsuragi!
- Ryuga turning the Dragon Fullbottle silver, which, according to Shinobu, is indicative of Hazard Level 7.
