Well it really depends on who you ask. It's true that Koogi never intended it to be BL but many consider it to be (the ones that ship them two) (¯―¯٥) just without "real love". And yeah it's psychological horror and drama, also not BL, but so much easier to categorize it as yaoi than explain what it actually is...
. . . You are aware that on the website KS was posted on, it was categorized under the BL genre, right? Koogi herself, despite what you claim, has actually spoken explicitly about why she chose to create a BL with such problematic themes. It being an abusive relationship doesn't change the fact that it is still a BL, BL as a genre (which is a synonym for yaoi; yaoi itself is an outdated term) isn't limited to just healthy depictions of a relationship
killing stalking is a yaoi, do you not know what yaoi means? its literally gay sex. gay sex occurred in killing stalking so obv its a yaoi.
yaoi ≠ romance. the artist only said that ks is not a romance genre because its not but its undeniably still under yaoi genre because of the main characters fucking.
Killing Stalking isn't a BLnso why'd u add it in this list