As of S.D. 10, Lias Warren is the captain of the Astral Knights. He first meets Edge Maverick and the crew of the SRF-003 Calnus after the rogue Black Eagle steals most of the stock of ingredients for the cure to Stone Sickness. After the Black Eagle is defeated by Edge at the Tatroi Colosseum, Lias thanks the hero for his deeds.
Edge is later informed of several issues by Lias, which include the "Ogre Battling" and "Ruble in the Caves" quests. In the latter, Lias troops join the SRF crew in a raid into the Astral Caves so as to cleanse it of a monster who is causing earthquakes in the area.
A war hero of Astral, Lias is Cyuss's father and Phia's foster father, and the keeper of the Bladeless Sword, a very powerful weapon left by the Old Race which was used against the forces of Asmodeus.
In the storyline, Lias is a target of Asmodeus, and is attacked by Demon World forces twice. For the first time, a demon disguised as Phia attacks him on his chambers. He survives, fortunately. In the second attempt, an entire army is sent by Asmodeus in order to retrieve his Bladeless Sword, although they are defeated by the Astral Knights and Roddick Farrence's group.