“glowfic” apparently. written in a roleplay forum format.
This is not a story for kids, even less so than HPMOR. There is romance, there is sex, there are deliberately bad kink practices whose explicit purpose is to get people to actually hurt somebody else so that they’ll end up damned to Hell, and also there’s math.
start here. or don’t, of course.
“And then I made the demons build a half pipe the size of the grand canyon, and I did tricks that have never been done before, and the girls all watched and were impressed.”