Once the mighty Black Dragon Monarch betrayed by trusted subordinates, my remnant soul is reborn inside a dragon egg and bound by contract to a human girl. I awaken a devour system to regain power by absorbing spirit materials and monsters. The girl strives to save her elder sister. I accompany her to explore secret realms and hunt treasures, meet kind companions and confront foes. We gather elemental origins and retrieve my lost sword. After avenging old grievances, I settle down with my companion and build our peaceful haven.