Avan De Ziniur III was the previous hero who defeated the Demon King Hadlar. When he was younger, he befriended princess Flora, the ruler of the kingdom of Carl, and Loca, the general of Carl's army, usually goofing around behind his thick glasses to hide his true power from everyone. When Hadlar tried to murder Flora, Avan decided not to hide anymore and protected her and the whole kingdom from the Demon King. After temporarily defeating him, he embarks on a journey with Loca where he would meet with Leyla, Maam's mother, and Matoriv, a powerful magician to finish off Hadlar for good. After their victory, he decided to become a trainer for a future generation of heroes. When Hadlar is resurrected and comes to defeat him, Avan casts the self-sacrifice spell Megante to protect Dai, Brass and Pop.
It is later revealed that Avan had worn a protective talisman (given to him by Flora) that saved his life from the effects of Megante by taking the damage on his behalf. Having survived, he then chose to level up to be of more use to Dai and his other students in their fight against Vearn.