The Chaos Dream was forged by the dragons, high elves and angels in order to fend off against the Savior's lunacy. It prolongs the Savior's sleep and since his awakening is closely related to the deviants' activities, the Chaos Dream has the ability to suppress the activities of the deviants. The Chaos Dream also has the power to intercept the Savior’s powers and prevent more people from descending into depravity and lunacy.
It was originally given to the Dreamwalkers, who showed some resistance to the whispers of the Savior. The Dreamwalkers were naturally able to control it. As eras went by, the heritage of the Chaos Dream disappeared leaving only a sliver in the Arde House. The Arde House, with great cost, was able to retrieve the Chaos Dream but had to split into seven houses including the Ascart House due to being in pursuit of the Savior's followers.
In the Third Epoch and potentially till now, Astrid Arde protects the Chaos Dream in the Dream Realm.