Is this passage all correctly worded and structured?

By 422 AC, Onysablet found her domain under assault by a former Hero of the Heart, Dhamon Grimwulf, who was now cursed and trapped in the form of a shadow dragon. Dhamon sought only to recover his lost humanity, and finally confronted the overlord in the depths of her swamp. After a prolonged battle, Dhamon defeated Onysablet, but he followed the black dragon into death just moments later due to his wounds.