TV-Series
Description
Kaiserin Underg is the current ruler of the Underg Empire, an antagonistic force that opposes the main characters in the anime. She is a female leader, notable as the first to hold this position in her organization for several years. As the empress, she commands her subordinates with an iron fist, showing no mercy for repeated failures. She is known to reprimand and even attempt to purge those who disappoint her, including her own generals. Despite this ruthlessness, she holds a deep, singular trust in her second-in-command, Skierhead, referring to him as the only one for her and relying on him completely for managing the empire's operations.

Physically, Kaiserin Underg has a humanoid form with red hair, yellow eyes, and dark lips, often dressed in a red, white, and black dress. Her appearance is distinct from many of her beast-like subordinates. In terms of abilities, she is immensely powerful. She can manipulate lightning, using it to execute punishment from afar. She also wields a potent dark energy called Underg energy, which is strong enough to easily deflect or break the combined ultimate attacks of the Pretty Cure team with a single hand. Her power level is such that she overwhelms the main characters upon their first direct confrontation.

Her motivations and role in the story are deeply rooted in a 300-year-old grudge. She immediately recognizes the infant princess El-chan and harbors a fierce, teeth-gnashing hatred for her, believing she has waited three centuries for revenge. This vendetta is linked to a past conflict between the Underg Empire and the kingdom of Skyland. Three hundred years prior, Kaiserin Underg was not a villain but a child princess. She was a kind-hearted girl who hated fighting and would cry when witnessing her father, the previous Emperor, invade and devastate Skyland. Alongside a young Skierhead, she opposed the war and secretly sought out Princess Elaine of Skyland to arrange a peace treaty.

On the appointed day for peace talks, her father betrayed her and launched a full-scale attack. As the Skyland warrior Cure Noble fought the Emperor, the young Kaiserin broke free from confinement and threw herself in front of her father to shield him from an attack, suffering a severe, near-fatal wound to her chest. In her dying moments, she begged for her father to be forgiven, an act that ultimately moved both sides to sign a historic peace agreement. It was later revealed that this injury never fully healed, which is why she remained hidden for much of the series.

The Kaiserin seen in the present is a tragic inversion of her former self. At some point after the peace was signed, her memory was altered. She was led to believe that Cure Noble was the one who murdered her father, rather than injured her while protecting him. This manipulated memory transformed her into a bitter and vengeful empress who seeks to destroy El-chan, who is connected to the legacy of Cure Noble. Her key relationships are central to the plot: she is the daughter of the previous Emperor, the sworn enemy of Princess Elaine's descendant, and the master of the seemingly loyal Skierhead.

Throughout the story, she remains a distant, shadowy figure for most of the series, communicating only through a distorted voice and silhouette. Her first physical appearance occurs late in the narrative, where she immediately defeats the Pretty Cure team. Upon learning of the past, Sora Harewataru and her friends attempt to reason with her, but her rage is unshakable. However, her purification by Cure Prism's "Prism Shine" ability not only cleanses her corrupted heart but also heals the ancient wound in her chest. This act frees her from the cycle of hatred, and she ultimately learns the truth that it was Skierhead, not Cure Noble, who was responsible for the final deception and death of her father, allowing her to finally be free of her past.