After the battle between Vorfeed and Dark Star Dugradigdu ended, Erulogos, along with Sirius and Armace, set out to find a way to destroy Dugradigdu and save their world. They learned of Dark Star's five weapons and that they were hidden in the Slayers universe. Out of the three of them, he was the most skeptical about the method to destroying Dugradigdu and did not believe it would work.
Unlike Sirius and Armace, Erulogos enjoyed fighting, showed no compassion for humans, only wanted to save his own world, and had no problem starting unnecessary conflicts as long as he achieved his goals. This caused him to constantly bicker with Armace and ultimately killed him after he failed to get the final Dark Star weapon from the Slayers. In the final battle, Valgarv, who had briefly been working with Armace in trying to get the weapons and who had fused with Dugradigdu, killed Erulogos, leaving only several fragments of his armor behind.