Gengo Aoi
Dr. Gengo Aoi is the grandfather of Kazuya and Kazuha, and a member of the Chevalier. He is the scientist that developed the Pandora, Limiters, and Stigmata. His newest project is aptly named Valkyrie, it was meant as a counterweight to Pandora, but was brushed off, however as of recent events it has been reintroduced and activated.