Tomorrow Woman:
She was created jointly by Professor Ivo and Professor T. O. Morrow to destroy the newly formed JLA. She became a member based on her telekinetic abilities which she claimed were the result of a "mutant 4 lobed brain." In actual fact, she was a living bomb designed to go off at a specified moment and kill the entire JLA. Eventually though, she denied her purpose, discovering the concept of freedom that her creators had deliberately left out of her programming. She sacrificed herself in order to stop a futuristic war machine by triggering an EMP bomb located in her body, which was originally intended to wipe the brains of the League. It was revealed that Morrow had seen this coming and was thrilled by it. He and Ivo had frequently argued about who had done the better work on her. Ivo thought that the body he had made, which was realistic enough to fool even Superman's heightened senses and x-ray vision, was the true work of genius. Morrow proved him wrong however, as the brain he himself had created was sophisticated and "human" enough to discover free will, even though the concept had not been included in her original programming.
As I recall, the cyborg chick in "Soon" was built by the mad scientist (albeit put together from parts), and was a bomb designed to take out the supers...