When I first saw the listing for Ghoul ga Sekai o Sukutta Koto o Watashi dake ga Shitteiru I mistook it for a Tokyo Ghoul spinoff. And as it happens there is a notable resemblance there, albeit one cut with Goblin Slayer… which is to say it’s pretty dark (rape, gore, body horror). Not sure I want to follow it any further to be honest since event developments seem kind of haphazard.
Generally the best you can hope for from an LN claiming a villainous protagonist is an anti-hero, with them far more often just featuring a normal hero who uses underhanded tactics. Gekka no Shoujo Asura‘s though is shockingly enough an actual villain, an ‘incarnation of malice’ not too dissimilar from what you’d get if Tanya from Youjo Senki happened to be a sadomasochist who loved both war & death. I’m interested to see where it goes despite there being some issues with gratuitous fan service and questionable structuring.