Julius is a prince within the royal family of the other world. He is introduced as a distinctly unlikeable character whose behavior puts others at risk. His most notable action in the early part of the story involves willingly endangering the protagonist, Seiichiro, despite having full knowledge that Seiichiro has a dangerous non-resistance to magicules. This callous disregard for Seiichiro’s safety marks Julius as an antagonist driven by malice rather than simple ignorance or naivete. He holds a personal dislike for Seiichiro, which fuels his willingness to leave him in perilous situations, such as abandoning him in a carriage knowing the danger it posed.

Julius shares a familial connection with another character, Norbert, though the two are half-brothers who only share the same father. Despite his initial presentation as a prince who is insufferable and cruel, there is an indication that his character is not entirely static. The narrative suggests that he does undergo some development, becoming better as the story progresses. However, for a significant portion of the plot, he remains a figure whose actions create serious obstacles for the main characters. No detailed information is available regarding his motivations, notable abilities, or background beyond his royal status and familial ties.