Mistress is an enchanted axe that belongs to Artemis of the Bana Mighdall. At the age of sixteen, Artemis tried to claim a different weapon, but because such weapons choose their owners, she was rejected. At some point, that same weapon was lost, and Artemis left the Bana to find it. Because the weapon she felt was meant to own was gone, she settled on a weapon that did choose her; Mistress.
This weapon is extremely powerful. It is bulletproof, and Artemis wields it well enough that deflects bullets as well as Diana can with her bracelets. Mistress is also extremely powerful to the point that it can pierce the flesh of a Bizarro clone. However, there is one drawback to using Mistress. Artemis has a special connection to Mistress so that whenever the axe is damaged, Artemis experiences that damage as physical pain. Because the pain is not the result of physical injury, even small amounts of damage can cause Artemis to double over in pain despite her Amazonian durability.