KAY/O (Kingdom Anti-Yield Operative) is a cybernetic robot from a future alternate timeline. He features a metallic body with a screen for a face, legs made of a mix of leather and metal, and visible energy lines throughout his body. He wears dog tags and a blood-stained cloth belonging to Brimstone around his neck. Modeled after Brimstone, his height is estimated to be around 190cm. Created to protect humanity in the war against Radiants, he succeeded in killing Reyna but suffered the tragedy of Brimstone's death and the devastation of Earth. To prevent this future, he traveled back in time to the present and joined the VALORANT Protocol. His abilities consist of FLASH/drive, FRAG/ment, ZERO/point (a suppression blade), and his ultimate NULL/cmd, which suppresses abilities in a wide area. His primary weapons are the Odin and rifles. He shares a deep bond with Brimstone and harbors intense wariness toward Radiants, especially Reyna. His greatest trauma is the death of Brimstone and the failure of the war, a scene that was directly revealed during Fade's blackmail.