Before it was destroyed in Thor: Ragnarok, the God of Thunder's enchanted hammer Mjolnir was arguably the most celebrated weapon in the MCU. "Whosoever holds this hammer, if he be worthy, shall possess the power of Thor" is the enchantment Odin placed on Mjolnir, so it's easy to think...
Instead, what Agatha did back when she was alive in the 1700s is make up the Road to lure unsuspecting witches and steal their power and murder them all so she can have all their powers. She killed thousands of witches for centuries with this stupid fucking con. When Billy came to her...