Lucifer Morningstar

Lucifer Morningstar is retired from Hell, and currently runs a piano bar called "Lux" in Los Angeles. Always at his side and helping him with the business is his Lilim female consort, Mazikeen.

Background
Lucifer was a member of The Host, and when he fell he was part of the The Triumvirate of Hell.

When he got fed up with how humans blamed him for all the wrongs in the world, he kicked everyone out of Hell and handed the key over to Dream.

He started a piano bar in Los Angeles called "Lux."

He is really pissed off at Yahweh and wants to give him the middle finger in many ways, however, Lucifer seems to feel like he always ends up at the butt of things thanks to Yahweh.

Personality
"Lucifer is portrayed as sophisticated and almost charming, similar to the stereotypical Christian devil. Beneath his charisma, however, Lucifer is a deadly and Machiavellian character, with no regard for human life or indeed any life other than those he can use to his advantage: a proud and vindictive fallen angel who has no qualms using powers second only to those of his father, Yahweh. In fact, Lucifer is described as having been the wisest, most beautiful and most powerful of all the angels in heaven, and he retains these traits even after his fall. Despite his egotistic and narcissistic tendencies, he does follow something akin to a code of honor - there are few beings in the universe he respects (his brother Michael and the Angel Duma among them) and only two he could be agued to care about (Mazikeen, his consort, and his niece Elaine), though his actions on their behalf are almost always for his own benefit, and it is doubted by all that he would help them otherwise. He also refuses emphatically to lie (which he considers crass and undignified), insists on paying back debts, and keeps his word - though this must not be confused with virtue."

Quoted from: DC Wikia