MarAuthor
most of the webnovel is spermatotoxicosis which requires not a thoughtful story but scenes +18 so I advise you not to pay attention to the toxic comments so you'll only ruin your health [not the first author I can remember who abandoned work because of this ] I wish the author good luck and continue writing [using a translator]
how about they can level but due to the uniqueness of each individual guardian they level up at different rates randomly which makes a valid reason to level up without seeming like you being lazy at the same time you do not have to state how much they level up ensuring that you don't have to stress about providing specific information