After the birth of Delia York the daughter of Damien, the embryo of her brother Alexander was placed into her body. While Dr. Louis Hastings a demon from hell was examining Delia when she was eight, he removed the embryo of Alexander from her and placed in into her adopted Mother Karen, to serve as a correct female body to give birth to the reborn Antichrist.
When Karen gives birth to Alexander he seems normal, but the mark of Satan 666 is on his hand. Delia then becomes the protector of the reborn Antichrist. When Karen discovers that Alexander is the Antichrist, she goes to him and Delia with the intent of killing them. However, Karen is unable to bring herself to shoot Alexander, and so instead shoots herself; leaving Alexander free to grow up to become the new Antichrist.
Damien Thorn the Antichrist, was now reborn as Alexander York.