Another design based off of one in high school.

Terra Kingston. In the story she was in, she became obsessed with the idea of love and the status of being in relationships and would do absolutely anything to get who she wanted, often manipulating others to get to her target. She believed that because it was for the sake of love, all her actions were justified. She later fell for a classmate who turned out to be a serial killer, and even helped him trap and murder a classmate under the condition that he would be her boyfriend after. He ends up killing her as well to "save" her from her obsession, but in the process provides the first and consequently only lead in the investigation.