"I don't know how to devour humans, but I can assure. I know how to devour dreams"
Constellation is known as "The mother of all Celestial Dragons". Although, for the fact that Celestial Dragons are humans who practiced the cult of Constellation, Constellation indeed has children, they were The Azure Dragon of the Blue Skies, Qing Long, and The Golden Dragon of Posterity, Seiryu.
Constellation came from the shreeded skin of Ahura who was given life and mission, to destroy the army of Bahd. Thus, given the right to devour humans. Constellation was indeed unstoppable as it dominated the skies of Bahd for a long time. But Bahd, made two of his children to stop Constellation, Ryu the Godslayer and Hebi the Vicious. As a great hunting begins and last for long time as one day, Constellation was successfuly defeated and slain by the two and put a curse on the dead body of Constellation, that only them can carry it. Later, Ahura appeared and thus found out that he can't take his skin back. Ahura confronted Ryu and Hebi and turn them into one and slain them.
Bahd hurriedly appeared to the two and seen them dying. Bahd made a choice, making them into stone that their soul will find its vessel as later it was called, the Grand Lotus.
Constellation roam around the world for so many eras. As it was used by different users,one of it is Nue. As later when Saint Gregory killed Seiryu, Constellation regain back her form and taken care by Shar. When it grew up, she regains her memories and rampage to the world. As Shar, was forced to killed her as the Fourth Grand Lotus.