Fiver was the R7 astromech droid that Anakin Solo modified and used during the first year of the conflict against the Yuuzhan Vong. During the assault by the Peace Brigade on the Jedi training center on Yavin 4, which occurred slightly more than a year after the invasion began, Fiver piloted Anakin's X-Wing as a diversion.
Despite damage to the X-Wing, Fiver successfully returned it to Anakin, and then boarded the transport that Anakin had repaired. As Anakin and Tahiri Veila readied themselves to flee, Fiver was present on the transport.
Throughout the battles fought on Duro, Yavin, and Froz, Fiver functioned as Anakin's astromech droid.