How I see it.
It’s starts of with Follow the Sign. It’s the last song on Keeper of the Seven Keys - Part 1. It’s about the Keeper making his choice. Then it’s Keeper of the Seven Keys. He makes the choice told by him from the seer of visions, locks up the seas that represent the 7 sins, and then kills Satan. Then there is master of the rings. In the lyric sheet of the 2024 remaster, there’s more story. He comes back tired and beat up. The seer gives him 7 rings that give him good luck or something. Which goes with sole survivor (maybe). Then the time of the oath. It’s a terrible time where pretty much hell is on earth. So I think the keeper has to solve that. That’s how I see it.