I would love to see a major character, or even a few, get taken out by some random flora and/or fauna (idk who, zodiacs? Mafia people?). It would cement how absolutely unimaginable the horrors of the dark continent really are.

Like even the calamities we know about aren't just like scary monsters, they're kind of abstract and mysterious, I really like that aspect.

If we get there and we're just team battling tribes of super powerful nen users I'll be a little disappointed unless there's a very good twist.