Answer:
Useful tool for who in darkness dwell. Within you, corrupting like a deadly spell.
I'm sometimes white and always wrong. I can break a heart and hurt the strong. I can build love or tear it down. I can make a smile or bring a frown.
Mobsters judge the quality of a vehicle by the size of this
Look into my face and I'm everybody. Scratch my back and I'm nobody.
I don't have eyes, but once I did see. Once I had thoughts, but now I'm white and empty.
What never gets any wetter no matter how hard it rains?