A girl with a mysterious past, Karen Erra is an orphan whose mother was killed by a Tengohg (a large native creature) at an early age. She has a close relationship with Maya Shidow, who she regards as a sister, despite not being related to. Despite being a Newman, she cannot use TECHNICs, because of a trauma she suffered at a young age. Karen is a very serious, focused person who fights as a Hunter and wields twin daggers.
At the age of 17, she became an instructor with the Guardians, and became responsible for teaching Ethan Waber and Hyuga Ryght. Although 'Karen Erra' disappeared during the events of Episode 1, Gurhal has perhaps not seen the last of this young woman.