Therestina Kihara Lifeline

Therestina Kihara Lifeline is the main antagonist of the second arc in the anime series A Certain Scientific Railgun. She is the granddaughter of Gensei Kihara, as well as his first attempt to create a Level 6 esper when she was a child, after which she became obsessed with perfecting his research, using the Crystallized Esper Essence created from the experiment. She was also the one responsible for the experiment that sent Harumi Kiyama's students into comas.

She is voiced by Sayaka Ohara in the Japanese version of the anime and Colleen Clinkenbeard in the English version, both of whom also voice Erza Knightwalker.

Trivia

 * Her "maniacal laugh" in the last few episodes of Toaru Kagaku no Railgun has been compared to Beatrice in the anime adaptation of Umineko no Naku Koro ni. Coincidentally, Sayaka Ohara, who Therestina in the Japanese version, also voiced Beatrice, who shares an equally twisted attitude. However, Therestina is a Complete Monster, while Beatrice is more of an Anti-Villain.