>>531659531
She was kidnapped by Merak for cheating at videogames and handed over to the underground Sumeragi Mengele division whom, after seeing she can bring back the dead, decided to try and turn her into a weapon against her will.
They did it via torture, both physical and mental, to manifest different more agreeable personalities. The first one they made is the insane one with the long rimming tongue, which couldn't be controlled, and then made the second more evil version that killed every single one of them in order to escape her torment.