The story with Davey Jones (going off of my knowledge of "Pirates of the Caribbean: Dead Man's Chest", anyway) is that he fell in love with Calypso, the Goddess of the Sea, and she gave him the job of ferrying souls across the sea to the underworld. The catch was he could only come on land for one day every ten years. On that one day, Calypso promised that she would be in her human form so they would be together. So Davey Jones faithfully carried out his duty, waiting patiently for that one day. But when that day came, and he went onto the shore for the first time in ten years, Calypso never came. He ended up returning to his ship at the end of the day, having never seen his love. Angry and heartbroken, Davey Jones decided to get back at Calypso. He tricked her into trapping herself in a mortal body, then left her to walk the earth as a human.

That's all I know of the story, and I honestly don't know if it's the full story.

But I hope it's enough of an explanation for Alex_the_kitsune 's next original bey design: Calypso Abyss Goddess.

Every pirate captain needs his goddess, after all.