I don't ses why the sect leader wouldn't know about the Realagar, why would she throw them in the lake othsrwise? But since they didn't recognize his monster form maybe they believe there's a monster hunting the area and they keep it away with the Realgar?
In part I was so sad when they brought up Ori and Tamon got sad but also I'm the malicious reader that hoping for it to happen so he would go mental.
The brick was actually from me urging them to not leave things undone.