Sigrid Kaslana is a bundle of energy and cheerfulness, with a dreamer's heart. As the daughter of Alfia, a member of the Hera Familia, and Kevin from the Zeus Familia, she is destined for greatness. Unfortunately, after a devastating battle against the one-eyed black dragon, most members of the familia, including her father, were killed, leading to the remaining members being banished from Orario.
Alfia farewell to her daughter, handing her over to her younger sister, Meteria. Despite being abandoned by her own mother, Sigrid knows that she had a valid reason for leaving her.
After being left in the care of Alfia younger sister Meteria, Sigrid eventually lost her too, as Meteria passed away after giving birth to her son, Bell Cranel a few weeks later. This left both Bell and Sigrid in the care of their grandfather, Zeus, who adopted them as his grandchildren. Although Sigrid was saddened by the losses in her life, she never let it dampen her spirited nature.
Inspired by her parents' legacies and her dreams of heroism, Sigrid decided to leave home and head to Orario when Bell was about one year old. She knew that in order to become the heroine of justice she always dreamed of being, she would need to hone her skills and strength as an adventurer. With the goal of protecting her baby brother, Bell, and the future familia she would meet, Sigrid was determined to become a strong adventurer. Despite the hardships and challenges she may face along the way, her sense of justice and unwavering determination would guide her on her path towards her ideal.
From her earliest days, Elliet sensed she was set apart. She possessed a strength and speed that surpassed all the children in her village. Because of this, her parents forbade her from revealing her extraordinary abilities to others. One day, while playing with her sister, Elliet unintentionally caused her harm. Consumed by anger and frustration, their mother confessed that Elliet was cursed and adopted. Heartbroken by this revelation, Elliet fled, embarking on a quest to uncover her true heritage. It was then that she discovered the world was far more expansive than she had ever imagined, filled with individuals who wielded power greater than her own. She was soon swept into the clandestine vandid society, a covert group of assassins comprising superhumans. Rising through their ranks like a dark horse, she quickly became the youngest and deadliest assassin in the world, earning the moniker "Dark Angel."
Meanwhile, on the other side of the world, Sonya embarked on a mission to find her missing sister. Fate intervened when she crossed paths with a young boy destined to become the king of a formidable nation. After saving his life and those of his bodyguards, Sonya was conscripted into the army. Following numerous successful missions, she climbed the ranks, becoming one of the kingdom's most formidable officers. How would Sonya react upon discovering that the assassin responsible for the death of the only man she ever loved was her long-lost sister?