Dragon Lord, Berserker Callion (ドラゴンロード、バーサーカーCallion "Doragonrōdo, bāsākā Callion") or simply Callion is the name of a dragon that ruled the hidden continent of Disgeum, the Draker continent.
This dragon is the deadliest of all dragons living in the world. Callion also IS the King of Dragons (Dragon King XIII). If you attempt to do something wrong in his terrority, his land or even his whole continent, he will find you and try hard to sense your presence so that he will get near you and kill you. It is rare if Callion doesn't attack you.
He firstly appeared in Disgeum Revrriors I as a final boss, and soon to appear in the anime (Season 6)
Callion was a dragon who was born in the Draker continent which was previously named as Ashtarethia. This was the continent where dragons only existed. He was actually the son of the Dragon King XII. Before his mother died giving birth, the previous Dragon King gave young Callion to Kakeru Ribenseji (great-great-grandfather of Ren and also a Dragon Tamer Sage).