Project Build

Project Build (プロジェクトビルド) was a top secret research project developed by Takumi Katsuragi. He conceived this project while studying Nebula Gas, believing he could harness it for some kind of use. He beagn his activities by covertly performing experiments away from the Touto Institute of Advanced Matter Physics' radar, for the purpose of mass-weaponizing the RIder system for sinister warfare. After he was caught and fired from the institute, Gentoku Himuro recruited him to join Faust in order to allow Takumi to continue what he had originally started.

Before Takumi Katsuragi's identity was wiped and reset, he had entrusted the plans of Project Build to his mother. Eventually after a struggle with Night Rogue and Blood Stalk, both Sento Kiryu and Ryuga Banjo are given the plans by Takumi's mother.

History
By harnessing the Nebula Gas from the Sky Wall and placing concentrated forms of the vapors in bottles, Takumi realized that it could take on the properties of something organic or inorganic. He then built a device that could harness the power of those bottles for an experimental weapon: the Rider System, which he called Project Build, as it relied on construction of two components to create a combat form.

File 001 - Build Driver and Fullbottles
After completing the Build Driver's construction, Takumi then did a video demonstration of his experiments on a secret computer file record, including a holographic combat simulation of Build's capabilities and showing its possibly limitless form changing potential. He show Build as Rabbit Tank Form to defeat 2 Guardians. He later showed the completed Wolf and Smartphone FullBottles before showing Build SmaphoWolf form said bottles would create on a data card.

File 002 - Transteam Gun System
Takumi later developed a device that allowed those who could not use the Build Driver to transform; the Transteam Gun, which allowed its wielder to gain power similar to that of a Driver user. He created Blood Stalk using the Cobra full bottle as the first prototype. He noted that the system was designed to push Build's growth potential further by challenging its limitations. The system also includes a voice modulator, a feature of privacy protection for its user.

It is also possible that the Night Rogue armor was created from this project as well.

File 00X - Sclash System
Upon accessing the file, Takumi congratulated the viewer as he shows his latest and greatest project, the Sclashjellies, jelly-pack like containers that contain Fullbottle essence, solidified as gel. However, Takumi admitted that this technology was unfinished and left its completion to Sento Kiryu. Sento does complete it, but the completed research was 'stolen' by Soichi Isurugi.

File XXX - Hazard Trigger
Takumi created the Hazard Trigger, which would later be dubbed the "Forbidden Item". However access to this file was restricted and required a password. Upon accessing the File, Takumi explained that the Hazard Trigger is meant to boost the Rider System power output dramatically. However, if used in combat for prolonged amount of time, the user will lose his or her rationality due to the overwhelming stimuli in the brain. Eventually, the user will possess an impulse to destroy everything in sight.

File ??? - Evol Restoration and Assembly Order
Evolto manages to blackmail Sento to complete the Evol Driver in exchange for Taizan Himuro's life. Sento found the blueprints of the Evol-Driver., written by his father Shinobu Katsuragi entirely in English. The file states that The Evol Rider is required to access the ultimate potential of Evolto's power, thus also giving the user full access to the Pandora Box. The Evol Driver is also made from parts from the Pandora Box, which is then assumed that the Driver is powered by the box itself. The file states that the only person capable of using this driver is Soichi Isurugi, who is in fact Evolto himself since he was captured.

File 1 - Enigma Development ResearchIMG_5573.png
By inserting the keywords Kaisei Mogami, Enigma and Kaiser System, this will reveal a journal written by Takumi during his time working with Mogami. The file states that Takumi helped in the creation of Enigma and he personally did some travels to the World of Ex-Aid.{Storylink|Kamen Rider Heisei Generations FINAL: Build & Ex-Aid with Legend Riders}}

File - 2 MutekiIMG_5572.png
This file contains a research about about Kamen Rider Ex-Aid including the Gamer Driver, The Maximum Mighty X Gashat and the Hyper Muteki Gashat.

Process
to be added