The Rift of Return can only be opened every 3,721 years. This is a reference to The Empire Strikes Back, when C3PO says "the odds of navigating an asteroid field are 3,720 to 1."
As Dareth is being chased by Kozu and the Stone Warriors, a person wearing a Lord Garmadon costume can be seen. While Dareth is examining the costumes, a couple human Anacondrai Cultists can be seen in the crowd.

The golden statue of Skales, which was previously seen in Winds of Change shortly before Morro possessed Lloyd, can be seen at the entrance of the Hall of Villainy.