Yua Yaiba (刃 唯阿, Yaiba Yua) is an engineer of A.I.M.S. who transforms into Kamen Rider Valkyrie (仮面ライダーバルキリー, Kamen Raidā Barukirī). She temporarily was the Fighting Jackal Raider (ファイティングジャッカルレイダー, Faitingu Jakkaru Reidā) before her defection.