Guest Stars Ross Marquand voices Ultron Cynthia Kaye McWilliams voices Gamora Ozioma Akagha voices Shuri Brian T. Delaney voices Peter Quill Co Starring Terri Douglas voices Additional Voices Matthew Wood voices Additional Voices Robin Atkin Downes voices Additional Voices Fred Tatasciore voices Additional Voices Helen Sadler voices Additional Voices Arthur Ortiz voices Additional Voices Kari Wahlgren voices Additional Voices Shondalia White voices Additional Voices Chuck Billy voices Additional Voices Justin Shaw voices Additional Voices