"And the terrors were sealed away by A’bbel and his Knights across the world. Imprisoned behind Gates to the Unknown, forged by the Goddess."
The Gates are doors scattered across the world of Exigo that keep Caen and his allies sealed. They are opened with two keys inserted at the same time - a vial and a trumpet. There are seven vials and seven trumpets, paired together for a specific Gate. The vials were born of the Knight's sacrifice, and are good. The Trumpets were forged from Caen's sin, each representing one.