The Weaponry Hero

is the sixteenth episode of Kamen Rider Build. Kamen Rider Grease makes a brief appearance in this episode, after his appearance in Kamen Rider Heisei Generations Final: Build & Ex-Aid with Legend Riders, as well as Akaba, Aoba and Kiba.
==Synopsis==
Gentoku’s words brought doubt to Sento’s ears! The fact that Sento is actually the demonic scientist himself has really brought him down. He keeps repeating to himself that he was the one who experimented on humans and created the monsters called Smash. Sento starts to fill with guilt. However, Ryuga speaks his mind. He knows he cannot continue to fight alongside him if he knows he was the scientist behind the technology that killed his girlfriend. Ryuga summons Sento to him by saying… “Fight me”…
==Plot==
to be added
==Cast==
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===Guest Casts===
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*Taizan Himuro's Subordinate: 
===Suit Actors===
*Kamen Rider Build: 
*Kamen Rider Cross-Z: 
*Kamen Rider Grease: 
*Blood Stalk: 
*Castle Hard Smash: 
*Press Smash Hazard: 
*Flying Smash Hazard: 
==Forms and Collectibles Used==
===Fullbottles===
*Bottle used:
**Build
***Biotic: Kaizoku, Taka, Ninjya, Rabbit, Gorilla (in Drill Crusher), Octopus
***Abiotic: Gatling, Comic, Tank, Light
***Other: RabbitTank Sparkling
**Cross-Z
***Biotic: Dragon
***Abiotic: Lock (in Beat Crosser)
***Other: Cross-Z Dragon
**Blood Stalk
***Biotic: Cobra
***Abiotic: N/A
**Castle Hard Smash
***Castle
*Form used:
**Build
***KaizokuGatling Form, RabbitTank Sparkling Form, HawkGatling Form, NinninComic Form, RabbitTank Form, OctopusLight Form
===Sclashjellies===
*Jelly used:
**Grease
***Robot
==Errors==
*When Blood Stalk throws the knife at Taro Satou that kills him, the knife's final location is seen on the wall instead of on Taro's back. 
*It's unknown how Build recovered the Octopus and Light Fullbottles as they were in Soichi's possession at the time.
==Notes==
*As part of Super Hero Time, this episode aired alongside episode 43, 
*Viewership: 4.0%
*Formula of the title: 2 \uparrow\uparrow 3= 2^{{2^2}} = 16()
*Fullbottles Obtained: N/A
*Closing Screen Fullbottles:
**Kamen Rider: Build
**Fullbottles:
***Biotic: Rabbit
***Abiotic: Tank
*Count at episode end
**Bottles in Build's possession:
***Biotic: Rabbit, Gorilla, Taka, Ninjya, Panda, Harinezumi, Lion, Kaizoku, Octopus
***Abiotic: Tank, Diamond, Gatling, Comic, Rocket, Syoubousya, Soujiki, Densya, Light
***Other: RabbitTank Sparkling
**Bottles in Cross-Z's possession:
***Biotic: Dragon
***Abiotic: Lock
***Other: Cross-Z Dragon
**Bottles in Night Rogue's possession: Bat
**Bottles in Blood Stalk's possession: Cobra
**Bottles in Castle Hard Smash's possession: Castle
**Bottles in Stag Hard Smash's possession: Kuwagata
**Bottles in Owl Hard Smash's possession: Fukurou
**Bottles in Hokuto's possession:
***Biotic: Wolf
***Abiotic: Smapho
**Jellies in Grease's possession: Robot
*This is the last Build episode airing in 2017.
*The third time Sento Kiryu narrates the recap by himself.
*This episode mark the last appearance of OctopusLight Best Match.
*It features the debut of Build's KaizokuGatling Form.
==DVD/Blu-ray releases==
*Kamen Rider Build Volume 4 features episodes 13-16: Who Takes Off The Veil?, The False Kamen Rider, Judging Sento Kiryu! and The Weaponry Hero.
*Blu-ray Collection 2 comes with 12 episodes.
Build_Vol._4.jpg|Kamen Rider Build Volume 4, DVD
91R_ZCOJk0L._SL1469_.jpg|Kamen Rider Build Collection 2, Blu-ray
==External links==
*TV Asahi's official episode guide for 兵器のヒーロー.
*Toei TV's official episode guide for 兵器のヒーロー
==References==
Category:New Kamen Rider Episode
Category:New Form Episode
Category:Christmas Episode