Obscenity manga refers to comics that have graphic and offensive sexual content. Such material often violates moral and legal standards. It can have a negative impact on the minds of readers, especially young ones.
It's possible that the cave holds ancient artifacts and inscriptions that tell the story of a forgotten civilization. The adventurer might find stone tablets with mysterious symbols that, once deciphered, could reveal secrets about the past, like how they built their cities or what their beliefs were.
Well, when we talk about pandering obscenity in fiction, it means that the author or creator is consciously including elements that are overly sexual and inappropriate, often just to attract attention or appeal to certain base desires. This kind of content usually goes beyond what's considered acceptable in terms of morality and good taste.
I don't quite understand the meaning of the phrase 'cold-faced pervert.' Can you provide me with more background information or a description of the novel that you want to read?