Arawn

The Great Demon King, he slept for a thousand years after his body is critically injured on the battlefield. Drwc resurrected him using a ritual involving Riannon as a living sacrifice, but is instead killed by Arawn after he saves Riannon from Drwc's control. When Arthur challenges Arawn while attempting to "save" Riannon from him, Riannon steps in by declaring him as their chieftain, taking them both by surprise.

Hisory
The Great Demon King, he was sealed away for 1000 years after his mortal body dies on the battlefield. Drwc resurrected him using Riannon as living sacrifice, but is instead killed after Arawn saves Riannon from mind control. She takes a liking to him instantly, and makes him chieftain of the Gael Clan. Arawn's true name, a name that awakens his power is Lucifer. He was the 13th Angel born after the previous 12 and was thought to be an imperfection. He became one of the 12 Angels after his "father" Angel, Myrddin died by performing the Song of Creation. He assumed role of his "father", opposed the remaining 11 White Angels, thus leading him to be exiled from Heaven, and became a Fallen Angel. He was the one who freed Primula and the humans from the bindings of the White Angels, as they had cursed mankind to praise and worship their creator until death. Throughout the ages, the White Angels hated him and opposed him on every occasion possible, eventually leading to his deep slumber after being struck by a cannon blast from a siege weapon. The element used in the weapon is Electrum in which Arawn's physical body is weak against. He then went into a deep sleep to recover his mortal body for the next millennium before the start of Tears to Tiara. However, he was awaken before his due time and his body has not completely recovered and so he has the body of a normal human being. Due to his nature, unknowing about the present customs, he takes in more wives after Riannon due to his blunts, actions and words.