My four-dimensional Gravity Falls demon, Pare A. Doxx.
He's a tesseract who prefers a human form who enjoys cake. Oh and he's got a 2D demon girlfriend, Star (who belongs to a good friend on Flight Rising). And as a human his third eye is blind but as a tesseract he can use all three and see time (and is constantly morphing so he's kinda hypnotizing). Also he's cursed, everyone he makes a deal with dies.
So yup. Demon teenager.
That is all.
Oh he's also a complete cinnamon roll. XD