In the 6th Century, Modred was an apprentice magician under Gervasse and betrothed to Gervasse's daughter Janice. Modred was asked to become an apprentice by Merlin. However, after hearing tales of madness, he declined. Thinking the power of the Darkhold could oppose the mad wizard, he went to the tower to claim it. He battled the Other (Chthon) until Janice came in. Rather than have her become corrupted, Modred gave himself up. Gervasse sealed Modred in a crypt hoping that future generations might be able to help him.
Modred was resurrected in modern times by Janet Lyton and Grant Whittaker. He was startled by the changes to the world but managed to protect the couple when the Other came to claim him.
Since then, he has fallen under and out of Chthon's control and encountered a great many heroes and villains. When Chthon's possession takes over, Modred is a very dangerous individual. One can never tell when he is going to change, but when Modred is in control of himself, he will help others fight evil, although his actions usually have his own interests at heart.