Bill Cipher, Discord, Black Hat and Alastor

Charismatic, calm, arrogant, introvert, polite, teasing, wicked, does not tolerate contempt, patient, violent, homicidal, talks like a radio program host stuck in the 30's

Alastor possesses shadow-related powers, which he obtained from a ritual he performed when he was still human. is also known as the Radio demon

Has short, red curly hair with black tips, fluffy deer ears and tail, deer antlers, red eyes, brownish-red skin. Takes with him a microphone that he WILL kill you if you touch it, always smiling with his pointy yellow teeth, wears formal clothing

Charismatic, manipulative, psychopath, masochist, teasing, show-off, playful, insane, arrogant, chaotic

Bill cipher is a dream demon who can mess with people's minds and can interfere in the world through the humans when he makes a deal with them. Bill cipher, despite being extremely powerful to the point of having the ability to alter reality, The extent to which it can affect Earth is limited (yet.) he can affect other worlds and galaxies, but he's more interested in the Earth and Gravity Falls (and the sixer, but shh)

A yellow triangle with black arms and legs, a top hat and a bow tie, has just one big eye.

Playful, jealous, liar, manipulative, wicked, chaotic, loving, doesn't take things seriously, catoonish, likes psychological horror

Can change the reality as he wants, usually to cause disorder. He is the spirit of chaos and disharmony

Is a mixture of several animals into a mythical creature called draconequus

pure evil. not more, not less. evil.
Being more specific, he is unsatisfied and irritated all the time, with the only exceptions being when someone is being harmed, is violent, selfish, speaks Spanish (BECAUSE HE IS MEXICANO!!! 🇲🇽🇲🇽🇲🇽) sadistic, arrogant

He is capable of anything as long as it is for the bad. The personification of the basic concept of evil

shown to be a black figure wearing a black top hat, he has multiple big, cyan pointy teeth, he wears a suit with a long bar. Despite the characteristics described, he can modify his appearance into the most imaginable forms.