I don't usually spoil much but you don't seem to get what I was talking about Gantz so I'll just say some things outright. What's not in O? There's no drugs. There's no rape. There's no sadism. And I'm just talking about that one mission. Series went on for over a decade with close to 400 Chapters, a hell lot of stuff happened before what you saw in O and worse stuff happened after. Just by watching O actually spoiled some stuff earlier but at least there are enough changes in it to mess with that. Remember that all its adaptations, including O, are meant to be self-contained. Even if you read the manga solely for that mission, you wouldn't understand much other than what you've already seen and if you do read everything till the end, well... I'm numb to it all but for someone like you, you'll definitely be affected by it, and not in a good way. I meant it when I said, "Gantz isn't for everybody, or most people even."
For the record, "loli" just refers to a character with childlike appearance, age doesn't even matter. Unless there're more letters to it or additional words or a specific context, don't always assume it has something to do with sex.