>>47614879To add to this:
When you get the keys, most of the content they could change is already finished and not repeatable.
Keys aren't kept when you start a new game, so you can't go straight from normal mode to playing on Easy/Challenge mode without being traded a key
You can't be traded a key you can obtain in your own game, so you CANNOT legitimately play through W2's main story on Easy mode, or B2's main story on Challenge mode.
