Dragon Slayer Eiyuu Densetsu: Ouji no Tabidachi

The Island Kingdom of Faaren exists in a remote place - far removed from other worlds by time and distance. A land imbued with magic, where sorcery and demons are as much a part of life as night and day, where the darkest imaginings of the mind can become real in an instant... Faaren was once a peaceful and happy realm, ruled by a wise king. Then darkness came upon the land in the form of the Demon Lord Ackdam. King Aswell's armies proved no match for Ackdam's demonic legions and he was overthrown and killed. Sirius, Aswell's young son, managed to escaped certain death with the help of Rias - the King's loyal minion. Years later, the Kingdom lies in ruins brought about by the mistreatment of the demon-rulers and Sirius, mentored byt Rias, has grown into a powerful young warrior. Trying to avoid Lord Ackdam's henchman, Sirius and Rias travel the Kingdom, protecting innocents from the evil that rules. But their deeds would not remain unopposed. The great demon Zagi manages to kill Rias and capture Prince Sirius. Rescued by the underground rebels, the Prince discovers that his Mother, the queen still lives captive within Ackdam's great castle. Resolved to avenge his parents and mentor, young Sirius must face the greatest evil this world has known and reclaim his throne.