Kai was just an ordinary person, but he got transmigrated on the novel he only read one chapter, and the rest of his knowledge about it is came from the fandom and some spoiler he got from the social media, he possessed a body that does not even a side character, villain, protagonist, it's just an extra, and in this world knowledge was extemely dangerous and a lot of weird creatures lurking at the darkness while something was staring at you on the sky so how could our protagonist survive in this world?, with him knowing a lot of forbidden knowledge, enough to turn him mad.
(Btw, it's not fan-fic, I just accidentally make it fan-fic but it's actually my owned novel, inspired with The Lord of the mysteries, however, the difference between the Lotm and my own novel, is unlike my glorious king Klein moretti, my main character will not die as a virgin and without a wife, basically my novel is both focused on romance and mysteries. don't worry my fml will not become burden on mc I'll also not make him annoying rather an extremely likeable and well written character but I don't know if I could make it but still, I read countless romance novel and stuff so I could probably managed it somehow right? back to topic, she will not become a burden since she would definitely become the strongest.
it's not a harem though, so don't worry.
I'm also bad at English, after all, it's my 3rd language but if you don't mind, it's worth reading)