Li Yentsui is a member of the Zoalord Council in Guyver: The Bioboosted Armour. Physically, he appears to be the youngest of the Zoalords, but this is merely due to the zoacrystals halting their users' ageing process. In human form, he appears to be a young man of Chinese descent with jet black hair. His Zoalord battle form somewhat resembles a humanoid mantis, with green skin and large prisms attached to his forearms.
It is unknown when exactly Yentsui was recruited into Cronos, but he is the seventh individual to be chosen by Hamilcar Barcas as a member of its leading council. Nothing is known about his activities before X-Day or which of Earth's provinces he governs following Cronos' takeover.
When Cronos Headquarters in Arizona is attacked by Zeus' Thunderbolt, Yentsui fights alongside Waferdanos and Dr. Barcas to protect the Sacred Treasure, a fossilized Ouranus ship that all of Cronos' advanced technology is based upon. When Gigantic Dark tries to steal the navigational spheres from the ship, Waferdanos attacks using his hair-drills while Yentsui transforms into his battle form, using his Zue Kong Zhan technique to produce inter-dimensional rifts around the battlefield. Although he and Waferdanos managed to injure the Gigantic Dark, the dark warrior ultimately tricked him into falling into his own trap - he was pushed through one of his own portals, straight into the waiting hair-drills of Waferdanos, which skewered him. The shock caused him to collapse his portals, and unfortunately he was only halfway through at the time. He managed to hang on for a few more minutes, thanks to the bio-energy from his zoacrsytal, and saved Dr.Barcas' life by creating a portal to the outside; surrendering his zoacrystal back to him, his final act in life was to mock the Guyver, as he was trapped in a base that would explode in seconds. He did not see how the Guyver and his companion Griselda used his one remaining portal to flee after Barcas.
As well as the psychic abilities typical of Zoalords, Li Yentsui is a highly formidable combatant in his own right. He is extremely agile and the prism blades on his arms can cut through just about anything, but what's even more impressive is their ability to produce localized rifts in space-time. Selecting two points in space, Yentsui can create "windows" through an interdimensional void and disappear through one window only to emerge from the other. He can open and close these windows at will and uses this technique - called the "Zue Kong Zhan" - to not only throw opponents off-balance by disappearing and reappearing in different locations, but it also makes an effective weapon for cutting his foes apart by closing the dimensional windows when an enemy is only partially through. Unfortunately for Yentsui, Agito turned his power against him and was able to defeat him in this manner.