The Holy Dragons, or Arch Dragons, protect the Ancient Tomb, the Great Library in which all information they have recorded is kept, including that of Nowe's birth.
In Endings A and C, the Holy Dragons are called upon by Legna to begin their fight against the Gods, but Seere defeats them by using his army of Golems. After fighting with Nowe, Legna becomes a holy dragon. His appearance now resembles parts of the library, with a column clasped inbetween his feet.
In Ending B, Legna and Nowe lead the Holy Dragons into battle against the Nameless. A Holy Dragon carries Eris alongside Legna.