Leader of the gods and the strongest being ever. He's the only remaining ancient god alive from more than 100.000 years.
100.000 years ago in the war between the ancient gods and the ancient dark ones he was the strongest gods warrior and he defeated the ancient dark ones and chased them down to hell.
The ancient gods' leader Pan Gu feared his power and ordered him executed.
When Hei Long came back from chasing the dark ones he found his beloved wife, Bai Long, almost dead by the gods decree. In a burst of anger he killed his own race and murdered all the ancient gods except him and Bai Long. In the end he couldn't save her but he tried to collect enough blood crystals to revive her.
He brought 10 chosen humans children, removed their souls, and put in them some transcendent vigor from the ancient gods, thus creating the new gods only to help him collect crystal.
For a 100.000 years he stayed hidden in his cave to save Bai Long from any harm and collect the blood crystals needed to revive her.