I know you’re not asking me but I have for real, in a little shamanic healing group I was part of, this guy was irl-trolling (but it took us a while to find out).
He told us he’d sold his soul, the stuff he described seemed legit, and there was a weirdness, not healthy or powerful, more like something inside him. He wasn’t some cool supervillain, just a bit of a jerk.
My relative Varnaxis did the same and got a completely different result, BUT he already had power and past-life stuff, so he didn’t just stumble into it. And I respect his accoimplishment but still know it’s not the path I’d choose for myself.