This Beggar is a Dragon God

Karen, the true heir to the Red Dragons, survives a coup led by his stepmother Fiona and half-brother Marcus by living as a beggar and mastering his Black Dragon Soul in secret. Years later, the Blue Dragon princess Isola, whom he once rescued, publicly kneels and asks to marry him. Their engagement awakens a curse that reveals Karen’s royal blood and Dragon God power. As Fiona and Marcus turn into evil dragons, Isola’s Ice Dragon power joins him in battle, allowing Karen to awaken the Golden Dragon God and destroy them himself. With the two kingdoms reaching peace, Karen and Isola are married, and a lasting era of harmony begins.