The moment you turn evil you get sith-faced.
I supposed the wrinkles and smelling like burnt broccoli come later.
Master Obvious: Hey, Clueless. I'm kinda worried about your apprentice.
Master Clueless: Whatever for?
Master Obvious: Well, he's wangsting more than usual.
Master Clueless: Not unexpected. He is young, after all.
Master Obvious: And he's developed a strong affection for wearing cowls.
Master Clueless: The kids call them hoodies these days.
Master Obvious: His skin has gone gray and eyes are yellow and he's incapable of looking at anyone directly, always has to have his head tilted down and eyes rolled up to glare.
Master Clueless: It's just a phase.
Master Obvious: Have you noticed his lightsaber's now red?
Master Clueless: Now that you mentioned it, he did force-choke a barista at the coffee shop for getting his order wrong.
Master Obvious: Either your apprentice is turning Sith or into a teenage vampire.
Master Clueless: If he starts to sparkle I'll shove him out the airlock myself.