Branchai is a truly unique variety of Hyper-Zoanoid that appears in the post X-Day period of the Guyver: Bioboosted Armour manga series. Instead of being a single specimen, Branchai consists of three separate bodies capable of fusing together into a single body. Separately, the Branchai Brothers are weak, but they unite in order to form an imitation of the Guyver Gigantic. In this form, Branchai possesses powers similar to the Gigantic, but not nearly as powerful.
In order to prevent the public from sympathizing with the Guyver, three of Cronos' leaders - Krumeggnic, Hayyan and Khan - authorized the creation of a new Hyper-Zoanoid capable of mimicking the Guyver Gigantic's form and abilities. Its purpose was to disgrace the Guyver in the eyes of the people and also to draw out Sho Fukamachi and fellow Zoalord Friedrich von Purgstall so that they could battle one another. The Branchai Brothers combined into their fake Gigantic form and were dispatched into Tokyo to wreak havoc, making the public believe that the Guyver was responsible for this act of terrorism. As the renegade Zoalords anticipated, Sho would not stand idly by while innocents were hurt and rushed into battle with the Gigantic. Branchai was no match for the real Gigantic and was quickly eliminated.
The Branchai Brothers were not shown fighting individually so it is unclear what abilities they are capable of in a separate state. Combined, their gestalt form imitates that of the Guyver Gigantic, though Branchai cannot imitate the Gigantic's full capabilities (Cronos were not even aware of Gigantic's full abilities by the time of Branchai's creation).
Branchai-Alpha forms the shoulders and head of the combined body, Branchai-Beta forms the arms and torso, and Branchai-Gamma forms the legs. When combined, Branchai is capable of using chemical explosives discharged from the forearms, can fire lasers from the forehead and can also fly.