Nailkaiser is one of Phantom Lady's chief minions. She appears in the very first episode of Angel Blade. She has the ability to grow up to three penises at the same time. In the 1st episode of Angel Blade Punish!, she is sacrificed by Phantom Lady, who claims that "You sacrifice what you love."

Luckily for her, she is saved by Angel Blade (who destroys the "chaos") and Angel Ender (who is shown holding Nailkaiser and Kyoka). The first episode of Angel Blade Punish! Nail has a flashback when Phantom Lady saves her from unseen dark forces, and transforms her into the mutant Nailkaiser. Nailkaiser's whereabouts are unknown at the moment, but there is some speculation that she may have something to do with Elphie, since she slightly takes on the same appearance in her Angel Beretta form, with her hair in high pigtails and white lipstick, not to mention her dark skin and green eyes. Elphie also recognized Widow's presence, and Moena saw a vision of Nail after Elphie caused her to orgasm.