Hyura is a prominent demon character, recognized as the current First Brigade Leader of Tooru Castle. She is a member of the Aharudo race, distinguished by their grey skin and pointed ears, and she has a slender build. Her long, light blonde hair is typically styled in a high ponytail, with two strands left to frame the sides of her face. Hyura is considered one of the most powerful demons in the war against humanity, possessing a recorded combat level of 52.

Her personality is defined by a serious and straightforward demeanor, a trait common among her race. Despite her stern exterior, she highly values her friendships and has a tendency to push her companions to surpass their own limits. Hyura is openly battle-loving and has a noted fondness for handsome men, sometimes showing interest based on looks and strength. This serious nature can also manifest in a playful cruelty, as her sense of entertainment sometimes comes at the expense of others. Her interactions often maintain a level of cool detachment, especially compared to more boisterous characters, though this facade relaxes slightly as the story progresses.

Motivation and role within the story are closely tied to her position of power and her ambitions. As a top contender in the tournament to select the next Demon King, she is driven by a desire to prove her strength. During the competition, she views the human hero Helck as her biggest threat and strategically plans to defeat enemies before he can act, demonstrating her tactical mind. Her role evolves from a rival contestant to a crucial ally in significant battles, particularly during the mission to retake Urum Castle from the Winged Knights.

Her key relationships heavily influence her journey. She maintains a rivalry with her fellow contestants, including the perceptive Kenros and the defensive Doruushi. Her dynamic with the Four Heavenly King Vamirio is notable; Hyura quickly sees through Vamirio’s disguise and treats her with a respectful formality that contrasts with her usual bluntness, though she adapts under pressure. One of her most significant relationships develops with Edil, a Winged Knight commander. Initially enemies, their repeated clashes during battle foster a complex bond, with some observers noting the emergence of a strange emotion between them. Hyura recognizes that Edil is struggling against the mind control inflicted upon him, and their fights become intertwined with a mutual respect and a growing, unspoken connection.

Throughout the series, Hyura undergoes significant development, particularly in how her initial animosity toward humans evolves upon witnessing Helck's actions. She begins with a deep-seated hatred for humans, bluntly calling Helck a "shitty human" and stating that if she became Demon King, her first task would be to eliminate humanity. However, as she cooperates with Helck in battle, she becomes more nuanced, observing his behavior and the reactions of others like Vamirio towards him. Her personal growth is also tied to her conflict with Edil, where her desire to defeat him becomes complicated by a growing awareness of his suffering and the possibility of him breaking free from control.

Hyura’s notable abilities are formidable and primarily stem from her Aharudo lineage. Her most famous trait is her incredible regeneration, earning her the moniker "Immortal." This power allows her to reattach severed limbs or regrow new ones within seconds, a capability she uses strategically, such as purposefully losing an arm to land a surprise attack on an enemy. However, this regeneration has limits and will cease to function if her energy is depleted. Complementing her healing factor is her immense speed and reflexes, which are sharp enough to impress even powerful foes like the Great Sage Mikaros. In combat, she fights as an expert swordswoman, wielding a knightly sword with great skill and ferocity.