Aju is a noble demon within the narrative. He holds the princess of Gandia captive, establishing his role as an antagonist. His actions instigate the central rescue mission undertaken by the demon hunter Laethreel. Their confrontation extends beyond physical conflict, fueling Laethreel's confrontation with unresolved aspects of her own origin. Aju's characterization is defined by his demonic nobility and his antagonistic objectives centered on his opposition to Laethreel and his captivity of the princess.