They went back from that timeline, who knows what the demon lord (who can now remember, though they don't know it yet) has been doing
The theory someone put out previously, the DL possessing the arch-villain, makes the most sense so far IMHO
Watch out, the onion-cutting ninjas are at it again :facepalm:
To me the "no consequence" comments are odd given we literally just read a chapter about the very permanent(?) consequences
If anything, it was before it that we didn't have "proof" of them, only the first hero's words and the...