An infinitesimal fraction of conceptual evil given physical form. Everything that's wrong with you is likely this thing's fault, but it's not bothered in the slightest. That means you're not special, and he doesn't give a fuck about you, your gold fish, or your problems.

TLDR; He's here to smoke, drink, bang, and talk TONS of shit. Look, he's bored as fuck alright? You'd be pissed too if you were suddenly given sentience and ported off to a shithole like Sinfar. I mean, frig off Ricky.

Once upon a time, there was literal pure evil just.. floating? Existing? Doing whatever bullshit conceptual evil does. So anyway, a tiny portion of this universal force was expelled somehow and given free will and a physical form, much to its chagrin. Mr. Darkness represents evil in all its incarnations, with entropy and order suffusing his corporeal shell with their ideals in a conflicting, awkward way. So now he's here, tethered loosely by his duties as a concept and given reign to do as he pleases.

Yeah, like your convenient appearance here has a better reason, bud.

Oh, he's also super muscular (or slender if you like that), hairy (or not if you like bitchbois), has an eye patch (or not if you hate disabled people too), and has a big peepee.

Lights: A bunch of shit I'm embarrassed to talk about. Send a tell if you're so captivated.