"I wasn't high. I - this is going to be complicated to explain. But I guess you do deserve a proper explanation."
Deep breath. "When I was nine years old, I took candy from a stranger. I knew I shouldn't, but I'd never got a very clear picture of why I shouldn't. It was drugged. She took me to her house and... hurt me. Kept me there for a while. Kept hurting me. The police came, eventually, and she went to jail, and I went home. But... nothing was right, anymore. I didn't feel like a person. Home didn't feel like home. The world was wrong. It shouldn't have happened, because a nice lady giving you sweets shouldn't be able to hurt you like that.
"After that, it seemed like whenever I did something I knew I shouldn't, it went badly. Worse than you'd expect. I'd steal a pie and puke for days. I'd make fun of a girl's braids and her brother would break my arm. And I couldn't stop doing things I shouldn't. It just got worse and worse. And then I drank some liquor out of my parents' cabinet, thinking it'd make me numb and make it all easier to take, and instead I passed out and choked on my own vomit and I died.
"I remember dying, and thinking, at least it was over. And I wondered if I'd go to Heaven, even though it didn't seem very likely. And I thought, even Hell couldn't be worse.
"And my soul went down. And Hell tried to catch me, but my soul slipped past it, past everything, past the roots of the world tree and the burning wall that guards it. Into the nothingness. And it was just... dark. And I felt myself dissolving.
"And I was furious, suddenly. I was mad at the woman who'd hurt me and I was mad at the world for letting her. I was mad at myself for not knowing better and I was mad at everyone else for not teaching me better. I hated everyone. I hated everything. I hated the world, and I realized that the world had hated me, that everything that happened to me was because I was wrong, I was broken - and it made me so mad that I knew, all of a sudden, that I couldn't die. Couldn't let the world win. I'd kill it first.
"Um. To elide rather a lot of further exposition, I did try to kill the world. But eventually I just... got tired of it. Threw down my sword, all that. And I went looking for something else that would make my existence make sense. But when I stopped trying to kill the world, I realized that I hadn't actually stopped having my trouble with... temptation. It still went badly for me, when I did things I knew I shouldn't. And it got worse over time, until it was dangerous for me to do things I wanted even when they weren't bad. And if I went long enough, I started to have trouble telling what I wanted. And eventually, something I wanted would kill me, and the cycle would reset.
"When I arrived in your world, I was so deep in that state that I barely knew what was happening around me. I was surrounded by your slaves. One of them was saying you wouldn't hurt a child, another of them said they'd seen you do worse. And I wanted to kill you, because... I guess because you'd hurt people. Not that I haven't hurt people."
He sits on the ground, looking miserable. "So I killed you. And that killed me. And I woke up a few hours later on the surface. With a headache. I still remember the headache."