I just realized, the demon king was probably one of the final bosses for the Xion realm to deal with. In Liam's last life the Xion realm won, but Liam is making a lot of changes that are tipping the scales in favor of the demons this time.
There should be rewards from this. It seems like a hidden quest or event, at the very least reputation gain with the king and demons. You can’t forget stuff like that when you’re supposed to be writing about an MMO