Creao Everlasting is a principal character known for her spirited and determined nature. She is a teenage girl from the wealthy Everlasting family in the city of Totokanta, recognized by her long blonde hair and blue eyes. Having been sheltered for much of her early life and even bedridden as a child due to illness, she developed a strong desire to see the world and seek adventure. Her life changes when she encounters the sorcerer Orphen, who is searching for a magical artifact known as the Sword of Baltanders, which belongs to her family.

Personality wise, Creao is outgoing, stubborn, and brave, often clashing with Orphen due to her refusal to admit when she is wrong and her habit of teasing others. Despite her noble upbringing, she is athletic and possesses a strong sense of justice. She becomes excited in the face of danger and is confident in her own abilities, though she also struggles with feelings of insecurity. As the only member of her traveling group without formal sorcery training, she sometimes worries about being a burden, but she continually pushes herself to contribute and become a reliable partner to Orphen.

Creao's primary motivation is to join Orphen on his journey, initially using the pretense of protecting her late father's sword, which she inherited on her fifteenth birthday. However, her true reasons are a fascination with Orphen and a genuine desire to understand his mission to save his sister Azalie. Over time, her goal evolves into a heartfelt wish to be a successful and dependable companion to him, filling her life with the excitement and purpose she always craved.

In the story, Creao serves as a catalyst for the journey and a steadfast companion. She orchestrates a way to secretly follow Orphen when he leaves her home, effectively launching their shared adventure. Throughout their travels, she proves her courage numerous times, such as saving Orphen from a Guardian of the Treasure and destroying a celestial doll to rescue an ally named Mädchen. One of her most significant acts is befriending and adopting a young Deep Dragon, whom she names Leki, forging a unique bond that allows the creature to aid the group in battle.

Her key relationships are central to her development. Her dynamic with Orphen is a core element of the series, beginning with bickering and growing into a deep mutual reliance and partnership; by the end of the original novels, they have a family together. She shares a friendly rivalry with Majic, Orphen's apprentice, and is known to tease him and even alter his clothes to fit herself. Her bond with Leki is also crucial, as the Deep Dragon becomes her constant companion and a medium through which her latent magical abilities can be expressed.

Throughout the narrative, Creao undergoes significant development. She starts as a somewhat bratty and sheltered noble girl and evolves into a resilient adventurer who is unafraid to confront powerful enemies. Her journey is one of self-discovery, as she moves from feeling like a helpless observer to becoming an active, invaluable member of her group, ultimately saving her friends and finding her own unique strength. Her development also includes awakening her latent magical potential, which she learns to channel through her connection with Leki.

In terms of notable abilities, Creao is a capable fencer, having taken simple sword fighting lessons in a school war club, and she wields the Sword of Baltanders with some natural talent. While not formally trained as a sorcerer, she possesses an uncanny and latent magical capacity that she unconsciously channels through her Deep Dragon companion, Leki, who acts as a medium for her power. Her true strengths, however, lie in her courage, her quick thinking in crises, and her unwavering determination to stand by those she cares about.