"Simply put, on our challenge journey we had unleashed upon us a calamity that wiped out all of humanity"
This sentence makes no sense, humanity wasn't wiped out, otherwise they wouldn't be there to talk about it.
Here's the same panel from a different translation:
"So every time we take up this challenge, we flee back carrying an extinction level threat"
Now this makes sense
Also, not only this one sentence, but this whole scan in general seems unnecessarily wordy and confusing, i know it's a meme at this point that the hxh manga has a lot of text, but i saw the same information conveyed in a much more concise and understandable manner in other scans.