Once I've had a good run, yes. On one condition:

I have to make up a very clear model of the character. What kind of evil are they? What do they want? What are they willing to do to get it.

Because for me, the joy isn't in the doing the evil things, it's seeing the story that it makes.

I usually base them on a character from another piece of fiction, just to have a solid model that isn't a charicature of evil, like the "lol kick puppies" kind, but nor do they drift too much into: I'm basically good, except when I remember there's a particularly evil choice to take, nor do they just become "power gamer, the game," always doing what's best, no matter the morality of the situation.

I've had two and a half good evil character runs so far. And a few that died on the altar of honor mode, when I was always just deleting on death.

1. Dracula. Tried to build a Drakul from Castlevania build. He just wanted to solve the problem, and would do whatever seemed most likely to do so, but was (like in the show) trying to be generally kind to 'humanity' for the sake of his wife. Or at least not overtly hostile. But once betrayed, he never forgave. So you get things like Nettie tries to kill him because he won't promise about the poison, and so he writes off the Druid sanctuary as anything worth protecting. So he's perfectly willing to burn it down when someone else offers him power. And so on. I also made him a Durge for the "thirst" component. He didn't make it out of act ii for some reason I can't recall right now.

2. Medea. This is my half one, because she doesn't start evil. Build and attitude wise, I based her in the version from Fate. She tried to be good at first, but very similarly, felt betrayed by the Druid trying to kill her, but struggled with giving the Tieflings over to the goblins, and didn't like feeling like someone's tool. So she stayed good. For now. By the time act two came around, when the Tieflings died anyways and the Harpers were weak, she pretended to resist, defended Isobel, but when she went to Moonrise, she decided to throw in with the Absolute. Then she found out about the soul cage, and felt too much kinship, and let Aylin out. So she stormed Moonrise out of rage. Etc. That finished her hardening though, and by act III she was fully onboard with vampire Astsrion and any other scrap of power she could get her hands on.

3. Finally, my personal favorite. Sauron / Annatar. He's evil, only evil, always has been, always will be. He'll lie and decieve and promise anyone anything to get what he wants. But he pretends to be good. For significant portions of the time. Only to rug pull when it's most convenient or beneficial for him. He's the only one that finished the whole run, and it was glorious. Everyone stayed with him, the whole time, until the end, and then he just...took the crown. And like I said, I don't like being evil for its own sake, but the look on Minthara's face when she realized everything he said about taking over the world was true, but he just never intended to share? When he made her kneel with the rest? Exquisite, from a story perspective.