When I think "devilish", I think Faye.

Vixen, egotistical, lazy, devious, sly, a thief, a gambler, and sometimes a "good guy".
She does what she wants. She gets what she wants.
Not your typical "evil, malicious, wants to maim kittens" approach to devil, but hope it still counts.

I hope this style isn't too minimalistic for some people. In the middle of this vector I just stopped and liked it the way it was. Reminded me of one of those beauty salon advertisements. It just seemed to fit.
I may come back and create a new wallpaper with the finished vector or something, but in the meanwhile here's my submission :3