It’s from Don Juan. It’s not an answer to your question OP it’s just someone trying to look cryptic for the sake of it.
The darkness comes from you, it’s what you bring to your workings that matters. What is dark for you might not be dark for someone else.
Most people agree “darkness” involves baneful magick, trying to impose your will on the unwilling, death curses, that sort of thing. Try Baneful Magick or Works of Darkness by E A Koetting for a good overview that touches on a few currents, then follow on with what you are the most drawn to.
Since you are new, I recommend looking into the darkness in yourself by doing something like a Shadow Tarot pathworking, or pathworking the Qlipphoth. If you do not know yourself really well launching into advanced workings can trip you up and bind you into madness through your own shadows - you need to learn to understand and control them, not be led by the nose by them.
Not what I meant lol. I meant to some for example King Paimon is this scary or powerhouse being, but to some he’s this average individual. “most dark and sinister” is basically like that because to one an entity can feel intense but to another that entity feels average.