He is an old fashioned and polite demon which very rarely curses, but we see in the prequel comic, "A day in the afterlife", that Vox, (his main enemy) is the only demon in hell that can make him curse. It is also canon that he is a huge foodie and was taught to cook by his mother, who he loved dearly. He is extremely charismatic and likes to entertain, as we see in the canon episode when he sings his own version of Charlie's "Inside of every demon is a rainbow" 

The Prototype before I made the new one :)

Alastor is a polite, kind, and caring gentleman. He tends to take things too seriously and cant take a joke. On the surface he is a cold and unfeeling person but on the inside he has a heart of gold. He is not a rude person he's just... brutally honest because he'd never lie to anyone. he does not care about anyone's feelings except for Charlie, Lucifer, and Lilith. he also speaks french as a second language. He gets bored easily and hates long rants. 

He is a guard for the Morningstar family

An all powerful overlord on hell in the pride ring, of course not more powerful than Charlie and Lucifer but the most powerful sinner of hell. Not into love at all actually hates love but will kiss people as a kind gesture. Hates everything in regards to sex. 

The Radio Demon, is there more to say?

He just wants to read, man :(

Polyester has pale skin, red eyes, and gradient purple-blue hair styled in a bowlcut which covers his left eye. His accessories include a black choker and a black charm that resembles the kanji for "heaven" (天). He wears a sleeveless, V-neckline white spandex bodysuit along with white gloves. His bulge is also visible. Polyester has a very high ego due to the amount of new-age technology he uses. He also uses 'Gen Z slang' (AAVE) such as "On God" and "ick".