Lazuli

Android 18 originally named Lazuli when she was an ordinary human, is the older twin sister of Android 17 and Dr. Gero's eighteenth android creation, designed to serve Gero's vendetta against Goku. While her interests do not initially deviate from this expectation, her curiosity to activate Android 16, in spite of Gero's orders not to do so, leads Android 17 to take it upon himself to rebel and murder Gero. Eventually, Android 18 becomes a member of the Z Fighters.