Frenzied Vigilante's Pants

 are an epic drop in the legs costume class.

Obtained from

 * ? in Assault and Battery

Feats

 * Evermore - Collect all styles in the Vestments of Rage set (50 points) (heroes)
 * We'll Burn You All - Collect all styles in the Vestments of Rage set (50 points) (villains)