Xuan Chai is the messenger of the Gods.
He is an old and bald man with completely white eyes. His prescence also brings a foul stench with it, likely from the vulture that sits upon his shoulder.
Like many other Gods, Xuan Chai has a low opinion of humans. He is surprised by Zi Shou declaring his revolt, stating that many humans naturally know to fear the great Gods.
Xuan Chai walks thirty straight days without rest to meet Zi Shou. He delivers a decree from the Gods, stating that it appears Shou and his country of Shang have become not as obedient to the Gods. To reaffirm his loyalty to them, they want him to invade neighboring kingdoms and steal their resources as tribute to them. Shou disagrees with this, and burns the decree, declaring rebellion.
When the Zhou soldiers accompany the Gods to take over Shang, he informs Emperor Wu that he will be bestowed the title of Tian Zi once this crusade is over. He comments on the conquest, saying that Zhou is indeed formidable. He also comments on the complexity of the Gods' thinking, saying that they have no interest in wars but always appear in times of need. When Tian Kui decisively punches through Shou and his horse, Chai says that this was a waste of time on Kui's part. However Kui tells him that the other five Affiliations of Heaven have joined since this is a matter of utmost importance; Xuan Chai looks up in exclamation.