In my personal opinion, Lucifer would have many forms but would appear to those who see him as their ideal form of beauty in a person. As in being perfect in the eye of the beholder to better gain leverage and make them notice you. Lucifer is prideful. After all, who doesn’t listen to the voice and persuasion of someone they find attractive or who they love. Love and lust are pretty blind.
So Lucifer would be that person who catches your eye. Maybe the woman with short blond hair, quick wit, and shapely body that you can’t look away from. Maybe the tall guy with a leer that makes your heart skip a beat and laugh that makes a good shiver run down your spine.
Lucifer could be anyone, but always the one you can’t keep your eyes off of.
He’s the one you don’t know yet still worms his way into your mind.
And always a presence you want to submit yourself to.