Goddess of Daggers, Wielder of the Fifty Daggers of the Danids. The Magician, Major Arcanum of the Wild Hunt.
Related to The Danids, she was the lone sister who did not kill her husband on her wedding night at the behest of her father. After her disobedience, her father ordered the remaining 49 to also kill her and her husband, though they were successful in killing her husband, they were unable to kill Mnestra, who managed to defeat them all with just her dagger. She would take the daggers her sisters used, creating the 50 daggers of the Danids, powerful artifacts.
I have an idea. Maybe the weapon is still the 50 daggers of the danids but maybe the tarot is based off of Brutus. Maybe the dagger was given to Brutus by Nimue and it corrupted him and that’s what caused him to kill his emperor and become the tarot.