Commander of the demons army and the former demon lord, he was once slain by Avan and his companions. However, an even more powerful demon lord revived him, and he was made into the commander of his troops.
Originally just interested in settling the score with Avan, Hadlar's interest soon shifted to Dai after their first battle, when Hadlar got badly wounded by a still-novice warrior Dai.
The power granted to him by the great demon lord Vearn is to return with an even stronger body each time Hadlar "dies"; each time he uses that power the dark mark over his face will grow. The catch is that this is something he has no control over, which means he will be forced to serve Vearn for all time, not having even the right to die.
Although he initially both hated and feared Dai for placing his possition as commander in jeopardy, eventually Hadlar would realize the foolishness of his previous self, and would deem Dai as both a worthy rival and an individual worth all his respect.
He trades his immortality for a massive strength increase, becoming a hyperdemon. He creates "offsprings" from the chess pieces Vearn gave him, each one possesing both current and former traits of himself. Hadlar gives up on everything for a final chance for a duel with Dai and after a huge battle finally is defeated. Having lost his immortality in exchange for power, he dies without regrets.
The only surviving chess piece, Hym the pawn, became his successor. After his helmet cracks he is revealed to be like a younger, silver Hadlar.