Lexton Vilestream, or AP4D9, is a Symbiotic Intelligence Unit OC created by Team Aura, and the main protagonist of Auraprince Symbiotic Chronicles. He grew fond of the Auraprince's youngest-born son, who suffered and later died from an unnamed terminal disease (believed to be a form of Cancer, but is not confirmed), at which point the child forfeited his body as a vessel for Lexton to be able to take a physical presence. After fighting beside Team Aura against the wicked Umbra Cruciferi, he settled down alongside co-creator Maekir Vilemist in the rebuilt Blackroot City, at which point he founded the Aura Busters as the leading police force. He later became a member of the Illidar League Elite Four specializing in Electric Types.