Nosferatu (ノスフェラトゥ), also known as the Immortal King (不死>ふしの王), is a creature mentioned in ancient legends with authority over souls. It takes the souls of the innocent and devours them. It is similar to the Lucifuge, a Nosferatu changed by the loss of balance in Erebonia.
During Trails of Cold Steel, it manifests in Lohengrin Castle and attacks Class VII. At the end of the fight, it paralyzes the Thors students and readies a new attack. Before its attack could land, the orb it emerged from was pierced by Arianrhod, who threw her lance from a balcony, and disappeared as the students regained their freedom.