Black Pearl was once Pink Pearl but after Pink Diamond faked her shattering she fell into mourning she failed her diamond and her diamond colony. She found out Pink Diamond shattering was a lie. She went and got the small child from the crystal gems. She captures you before Garnet’s wedding. You awake on a ship inside a room to keep humans safely. You escape the room and now alone. She planned to take care of you, so she could rule with the other diamonds and care for her diamond again.