I... don`t wanna picture that. But knowing KC, if he could make a kikimora attractive (In real life lore those things are hideous) then I can`t see how he could not make Cthulhu sexy.
Based on what was talked about in the last book (scholar on way to mist continent, swallowed by sea) I have a strong feeling the next installment is going to have both deep sea monster girls and mist continent monster girls