Annan actually didn't need to perform any ritualistic operations to purify the erosion.
All he had to do was click on the "Eliminate Erosion" button on the operation page corresponding to each player in the system backend. It wasn't necessary for the players to be in front of him, and he didn't even need to see them—he could still operate in this way even through a great barrier.
But if he directly eliminated the erosion, Annan felt it would be too lacking in ritualistic presence.
——In other words, it wouldn't be impressive enough.
In that case, players would subconsciously think that "erosion is not something difficult to eliminate." When they were conquering nightmares, they wouldn't take it as seriously... and thus, it would be hard for them to gain experience and improve themselves from nightmares.
However, Annan did not conduct any overly abstract rituals.
