Kagali, also known as the Curse Lord Kazalim, is a former Demon Lord and a central figure in the political undercurrents of the world. Originally a princess of a powerful and ancient elven kingdom, her life was shattered when her father, possessed by another entity, went mad. He stripped her of her power, killed her, and then resurrected her as a Deathman, a form of undead. As an act of cruelty, he cursed her new body, leaving it twisted and scarred, before forcibly transforming her into a male and renaming her Kazalim, calling her his son. Her homeland was later destroyed by the wrath of the Demon Lord Milim Nava, leaving Kagali as one of the few elven survivors.

Devastated by the loss of her loved ones, Kagali used a forbidden spell to resurrect her most faithful servants, creating the powerful Deathmen who would become her closest allies: Clayman, Laplace, Footman, and Tear. This group, known as the Moderate Harlequin Alliance, functions less as a collection of minions and more as a surrogate family, bound by genuine loyalty and affection. Despite her cruel reputation, she shares a lighter, friendlier side with them.

During her centuries as the Demon Lord Kazalim, Kagali was infamous for her cruelty, cunning intelligence, and destructive temper. She was a power-hungry schemer who preferred to operate behind the scenes, using her unique curses to enslave powerful beings and consolidate her political strength among the Ten Great Demon Lords. One of her greatest flaws, however, is her vengeful and ill-tempered nature, which has led to her downfall multiple times. A burning jealousy upon seeing the beautiful Demon Lord Leon Cromwell caused her to attack him recklessly. She lost the battle, and her physical body was destroyed.

For over a hundred years, Kagali survived only as a disembodied astral spirit, her consciousness slowly fading. She was saved when she encountered an Otherworlder named Yuuki Kagurazaka. She initially attempted to seize his body but failed and instead agreed to share it, forming a close alliance with him. Grateful for his aid, she became his secretary, all the while affecting the world through her subordinates. Later, Yuuki procured a female elf homunculus body for her, allowing her to be reborn as Kagali, an identity she uses to hide her past as the male Demon Lord Kazalim.

Her personality in this new form retains the core of Kazalim but has taken on a more outwardly feminine demeanor, speech, and mannerisms, a change that amuses her long-time servant Laplace. She remains fiercely loyal to Yuuki and continues to harbour an immense, vengeful grudge against Leon Cromwell for destroying her original body. She also swears revenge against Rimuru Tempest for the death of her beloved subordinate, Clayman.

Her motivations are deeply rooted in her tragic past: a desire to regain the power and beauty that were stolen from her, a need for revenge against those who wronged her, and a search for a place to belong after the loss of her kingdom. Over the course of the story, she is manipulated and controlled by powerful figures like Tatsuya Kondou and later joins the army of Michael, all while harboring traitorous intentions. After a confrontation and honest conversation with Leon Cromwell, she begins to find a path toward reconciliation and self-forgiveness. Learning that her father was possessed and not truly at fault further changes her perspective. Having lost most of her companions, she eventually seeks a new beginning and finds refuge within the Tempest Federation.

In terms of abilities, Kagali is a master of powerful necromancy and forbidden magic. She is capable of creating powerful undead servants, including high-class Deathmen like Clayman and Laplace. However, her current homunculus body is physically fragile, limiting her power and preventing her from reaching the full strength she once commanded as a Demon Lord.