Vows of Gold and Laughter

In a world where color is magic and belief is power, four misfit immortals are picked by fate.
Bai is as old as dirt (literally), and he's tired of learning, tired of killing, tired of living. So he retreats to his mountain, taking the key to the Underworld with him.
Jin needs that key. It is the only way to save her father, the Sun Emperor and ruler of the Heavens. But Jin is merely the Goddess of Beauty, and whoever cursed the Sun Emperor is now hunting her.
The only being who will help her is Xiao, the God of Pleasure and her future husband. But Xiao lives in a drunken haze; can he really protect Jin when he can't even care for himself?
Luckily Nanami, the world's second-best thief, knows what to do. Steal Xiao's Infinite Jug and don't steal his heart-even if she really wants to.
The meeting of these powerful but lonely beings will reveal secrets that could destroy the Heavens-and dreams that might save the world.