 Shortly after returning to the U.S., Sisneros joined the heavy metal band Crescent Shield in 2003.They have one album - "The Last of My Kind" - and are signed with Italian label Cruz del Sur Music and German label Pure Steel Records.In addition to Crescent Shield, Sisneros regrouped with Rustrum to form the Megadeth tribute Hangar 18, where she uses the stage name "Mellefson" (an amalgamation of her name and Megadeth bassist David Ellefson).