Ben 10 season 2 episode 9: Tough Luck

Gwen dons her Lucky Girl costume again upon finding the Keystone of Bezel at a convention in Las Vegas. Rather than magical luck, the Keystone increases all of Gwen's natural abilities, making her a more efficient and powerful heroine. At the same time, Hex has been busted out of prison by his niece, Charmcaster, and seeks to use the keystone to restore the destroyed charms. Charmcaster tricks Gwen into trusting her so that she could easily take the Keystone and give it to Hex. However, Charmcaster double-crosses her uncle so that she can take the Charms power for herself. Wildvine stops the recreation process and Gwen defeats Charmcaster herself. To do so, she instinctively fires an energy blast from Hex's staff which suggests an affinity for magic.