Crimson Gauntlets are mechanized gauntlets from Jun Mochizuki's The Case Study of Vanitas, capable of spouting seemingly unlimited amounts of fire in concentrated explosions. The Crimson Gauntlet belonging to Jeanne, Carpe Diem, is famous for having been used during the war between Vampires and humans, in which Jeanne used its power to execute many of her own kind after being recruited by Lord Ruthven as a Bourreau. For this, Jeanne has earned the title of "Jeanne the Hellfire Witch" and has become a figure to be fear among both humans and Vampires. While the full extent of the Crimson Gauntlet has yet to be explored, Carpe Diem has been shown to have been purposely crafted to extend past natural arm-length and was crafted from an unidentified crimson-colored metal. Furthermore, Carpe Diem possesses a pauldron, rerebrace and couter in addition to the main body of the gauntlet leading into the razor sharp clawed hand in which a central orb is placed in the center of the palm from which Carpe Diem's explosive power is released. Jeanne is shown to carry Carpe Diem in a large black coffin, though it's unknown if this is simply a carrying case she'd fashioned herself or whether or not this is the means in which Crimson Gauntlets are kept in.
- It is suggested that Carpe Diem is not the only Crimson Gauntlet currently in existence, however any others have yet to be mentioned otherwise.
- "Carpe Diem", the name of Jeanne's Crimson Gauntlet, is a Latin phrase meaning "seize the day".
- Is is as of yet unknown whether or not Carpe Diem belongs to Jeanne or Lord Ruthven originally.