Son of Air & Darkness Volume I of Tales of the Dearg-Sidhe

Dubhghall is a mighty warrior, trained by Scathach herself, made immortal by the Morrigan, who has taught him to feast on the blood of his enemies. He is the grandson of Lugh, no fire nor light can harm him. In the time of Roman rule, the Britons cry for justice, and he must decide whether to answer their call when he finds himself caught between the soldiers of Rome and the warriors of Boudicca.