Faith was my foil.
Even I could see that. Even as I was in the moment, and even as I knew that foils didn't exist in such a perfect state in the real world. And yet here she was. My opposite.
She saw the world as her playground, and she had that horrid motto about stealing whatever she desired. She preferred to party, dance, and have sex over researching the latest demon with her watcher. Her morals were as skanky as her clothing, and she always wore the most I-want-to-sleep-with-you-for-cash makeup. She didn't care about hurt feelings or justice, and she even went bad once, killing and torturing her way across my town.
She killed people on the majorly evil mayor's orders and she did it gleefully, reveling in each kill like a soulless vampire herself.
Yes, Faith was my foil. My opposite in every way. Too perfect to exist in the real world. At least, that was what I told myself because otherwise, I'd have to admit the truth. That Faith wasn't my polar opposite, after all. She was closer to my reality than I would ever admit to anyone. She wasn't my foil; she was my cautionary tale.