Board Thread:General Discussion/@comment-1031724-20161020032419/@comment-477304-20161021145237

Also, Gerald was referring to the Chaos Emeralds, he states outright that he created the Eclipse Cannon to destroy the Black Comet. Black Doom needed the Chaos Emeralds to bring the Black Comet into Earth's atmosphere and the Eclipse Cannon requires all seven Chaos Emeralds to fire at full power, so that's what Gerald was talking about.