Andrea Beaumont
Andrea Beaumont was the daughter of Carl Beaumont, one of the rich and powerful in Gotham City, but soon fell into the debt of gangsters. While attending college, Andrea met Bruce Wayne at a grave yard while she was visiting her mother's grave, and he was visiting his parents' grave. The two started dating and fell in love. Their romance grew so serious that Bruce (who had long ago made a vow to fight evil) proposed to her, and she accepted. But fate intervened and Andrea was forced to flee the country with her father after witnessing gangster Salvatore Valestra threaten her father over money he owed.
Several years later, while living in Europe, Andrea returned home to find her father murdered by a gangster who worked for Valestra, and in grief, Andrea vowed vengeance. She trained, and developed weapons and soon took the new identity of the Phantasm.
Returning to Gotham City, the Phantasm began murdering the gangsters who were responsible for killing her father, and was briefly reunited with Bruce Wayne, whom she soon figured out was Batman. But the Joker figured out who the Phantasm was, knowing he was a target (he was actually the gangster who personally pulled the trigger on her father). And the two battled at the Gotham World's Fair, with Batman in the middle. The park exploded, and Andrea and the Joker disappeared, both managing to escape, Andrea fleeing Gotham City.
Years later, she came under the employ of Amanda Waller for Project Batman Beyond. She was assigned to murder the parents of then eight year old Terry McGinnis in front of him as they left a movie theater, but for once, Andrea refused to "pull the trigger," telling Waller that if she was to honor all Batman stood for, she shouldn't commit murder to create another one.
Batman Adventures
Andrea took freelance jobs as the Phantasm, acting as an enforcer, spy, thief and assassin for any syndicates that met her price. However, she was an empty shell of who she once was, having lost everything that truly mattered to her.