What's the deal with the character? Is he supposed to be evil?
No, more just a case of growing up with the worst family in history.
He's narcissistic and mocks people endlessly, but he's very much more in the doesn't value human law and propriety zone rather than actively evil. One of the things that really sets him off is when people try to blame humanity's own bad things on him. Like, it really sets him off. I guess being history's ultimate scapegoat gets wearing.
His character makes sense in so far as:
- He's immortal. Not just ageless but in a "ow, you shot me! If you do that again, I'm going to get really pissed off" sort of way. Like a very nerfed superman. He bleeds, just not from small calibre.
- He has spent thousands of years as the Lord of Hell, served by a legion of fawning demons.
- He has perhaps literally the biggest inferiority complex in history given his dad is God and the entire human race despise him. Except Satanists - and he hates them even more.
So a lot of the show is him learning introspection for the first time in his existence. One of the other characters is his psychiatrist and there's a running joke of him always taking completely the wrong message from her suggestions. Basically, being up and living amongst humans and a certain spoilery thing I wont get into, begin his journey of personal growth. And boning people. Lots and lots of boning people.
The show is pretty spotty in the first season. Like JimiHendrix says, it's a police procedural so there's always this murder of the week thing that forms the skeleton of each episode. But it is only the skeleton. The meat, organs, skin and lips are the characters, the humour and the reveals. The crimes are there to get all the characters talking and doing stuff together. Lucifer ends up helping detective Chloe Decker out with a murder case in the first episode, finds it hilarious fun and worms his way into LAPD as a consultant and essentially pisses her off no end.
Second Season is a bit more even and in the Third they begin hitting their stride. Season 5 is released in two halves and I've watched the first half of the season and it's very good writing. Like, really good. The third episode of Season 5 is especially clever and very meta. The interplay between the few who know Lucifer's true nature and those who don't gets pretty neat. There's a line where someone says: "if the worst thing you said to him was 'go to Hell', that's pretty mild" and the look of "oh, if only you knew" on her face is good. Also, I don't know how well it will work without context but a character (Linda) is suggesting baby names and says: "how about Michael" and gets a hilariously firm "No!" in response.
I've never read the comics but there's a rule in any discussion about Lucifer that every dozen posts or so, someone says "he's a different character to the comics".
Every. Dozen. Posts.
EDIT: This being Kiwifarms, it should probably be commented on how infected or not this show is with Woke. Well, it's obviously not anti-woke. And no especial reason it should be. Lucifer is bi- but that's hardly out of character and the vast majority of his partners are women fwiw. It's at the level of sexuality and race doesn't matter, rather being your defining identity, which is how things should be. It also at points manages to show the shallowness of open, meaningless sex contrasted with real affection without being religious fundamentalist about it. It even, very gently pokes fun at the super-woke on occasion such as when Maze and Chloe impromptu pretend to be the parents of a child when investigating a crime at a school. The PTA woman is super-delighted at the child having "two moms" and you can see is just itching to tell all her friends how supportive she is of that. The show has been pleasantly non-judgemental but like all good things, that probably can't last.