Central to the plot: Four sisters.
Tessa. The eldest. The aberration.
Alanna. False Lishaya.
Katrianna. The backup. Not just an empath, but a sorceress (yes, really the only one of her kind)... and the second-strongest empath in the world.
Name: Contessa Marie Stone. She only uses "ni'Tamra" under duress.
Significant Other: Adam Jones.
Background: Tessa was the first product of the Council's breeding program. Lacking sufficient power to be passed off as the Lishaya and, just as important, lacking the archetypical Tamrani appearance, she was sent away to be raised by the Council at one of their lesser outposts.
Tessa grew up ignored at best... until Jason, upon hearing of her existence, managed to extract her. She arrived at the Sanctuary at age ten. Painfully shy at first, she blossomed in the classroom and, gradually, in her peer group... she eventually because a sort of big sister figure to the younger Dasaroi at the Sanctuary. Like Shawn after her, she remained on as an instructor.
When she was in her early 20s, Jason approached her with an idea - finding and helping newly-active Dasaroi who didn't know what they were or what to do. She enthusiastically accepted, and has been on the road with Adam ever since... when she's not actively on the road, she maintains a suite at the Sanctuary.
At the time our story begins, she has never met her parents or any of her sisters.