Rathrea

The rathrea were dragons transformed by a secret ritual performed in Skelkor in Laerakond. Dragonborn called them ghost dragons.

Description
Rathrea were created when dragons failed to awaken after having consumed arambar. Those dragons eventually transformed into wraith-like, incorporeal glowing white spirits who had the ability to divine the future. This ability was limited to certain areas of information and timespans.

The rathrea didn't live for much time, fading away in a few weeks. According to Gauwervyndhal, those rathrea "ascended" after they disappeared.

History
The Empress Dragon Gauwervyndhal forced many of her dragon servants, even her own children, to consume arambar in order to commune with the dead primordial Arambar to obtain lost knowledge. She prized the rathrea for their prophetic ability as it allowed her to outmaneuver her enemies.