YMMV / Goth (2003)

• Complete Monster: Goth is a zealot who believes that the "true" goth lifestyle involves committing random acts of violence for fun. She kidnaps a young couple, Crissy and Boone, to teach them her ways. She commits various atrocities, such as raping a man, forcing Boone to cheat on Crissy under pain of mutilation, and torturing an old man. She eventually drugs Crissy and tricks her into killing Boone and everybody at a party, succeeding in her goal in making Crissy just like her.
• Designated Hero: Crissy becomes this when it's revealed that she went along on Goth's escapades knowing she was a homicidal maniac, meaning that she was a willing accomplice to a bunch of rape and murder, all in the pursuit of revenge.