||the Demon Dragon King, Ma-Ryu-Ou, Gaav
Gaav is high-ranking Mazoku, bearing the title of Chaos Dragon but unrelated to the other dragons of the world. For a long portion of NEXT, Gaav appears to be the main antagonist, though it was later revealed that he was simply a pawn in Hellmaster Phibrizo's plan. Before he started hunting Lina, he met Valgaav during the war of the extermination of the Ancient Dragon race and made the last of the Ancient Dragons his minion. Valgaav would then proceed to be a main plot driver in the next season, Slayers TRY. Long ago, Chaos Dragon Gaav battled with Aqualord Ragradia, and eventually defeated him. However before his death, Ragradia somehow managed to seal Gaav's Mazoku soul into a human body, dramatically weakening the demon lord. However he still displays a considerable amount of strength, far out classing that of Xellos who is unquestionably the strongest Mazoku outside the five demon lords. Even in a human body, he was still able to attack on the Astral Plane, as he once bested Xellos at his own game. Furthermore, he was able to withstand and survive a direct attack from Lina's Ragna Blade, considerably the second most powerful spell in her arsenal, second to the Giga Slave.