Whats a good last name for my character Darcy?

im writing a book, and Darcy is my main male character.
Darcy is a shape-shifter, his natural form is one of a man, a devilishly handsome man, he likes to trick people because he feels he must, when he gets captured by the SNF (supernatural federation not completely sure what they’re going to be called yet) he first appears as a young girl to try and escape. and want a last name that matches he’s character. and has a strong meaning.
Darcy = The dark one.