Princess Diellza von Katerinburg is the last surviving member of the once-noble von Katerinburg dynasty, which held sway over the principality of Katerin for over three centuries. The family’s loyalty to the Grover dynasty earned them the honor of ruling the blighted lands of Katerin, a region that would ultimately become a desolate wasteland following a brutal revolution.

As a child, Diellza’s life was shattered when revolutionaries stormed her family’s castle, slaughtering her parents, siblings, and everyone else within the von Katerinburg line. At the tender age of six, Diellza was left as the sole survivor of her bloodline. Imprisoned by the revolutionaries, her innocence was lost amidst the carnage. When the revolution ended and the Griffonian Empire was restored, she was raised to the throne as the Princess of Katerin, despite the deep psychological trauma that had taken root within her.

The violence and loss that marked Diellza’s childhood left an indelible scar on her mind. Her reign, which began with hope for stability in Katerin, soon descended into madness. As the last heir to the Katerinburg dynasty, Diellza was surrounded by nobles and advisors who formed the Katerintreue, a faction that was meant to support her but instead took advantage of her fragile state for personal gain. Diellza's grip on reality slipped further with every passing day, and she became increasingly known as "The Mad Princess." Her once-regal mannerisms gave way to erratic behavior, making her feared and unpredictable in the eyes of her subjects.

Diellza’s unpredictability became a defining feature of her reign. Her moods swing wildly from lucidity to violent outbursts, often without warning. Her subjects live in constant fear, never knowing what will trigger her next fit of rage. The chaos within the royal court has caused many to abandon their duties, and those who remain are either too loyal to leave or too fearful to act against her. Among her eccentricities is her attachment to a macabre gift from her cousin, Wingfried von Katerinburg—a pony's skull named "Glitterhoof." Diellza treats the skull like a stuffed animal, referring to it as her fiancé, further cementing her reputation as a ruler lost to madness.

Her erratic behavior and violent tendencies have stripped Katerin of its dignity and reputation. Once respected by the Herzlanders, the principality is now a laughingstock, its name synonymous with dysfunction and despair. As "The Insane," Diellza's reign has brought Katerin to the brink of ruin, leaving its populace trapped in a never-ending cycle of suffering. Yet amidst this chaos, a flicker of hope remains in the form of the noble Knights and Prelate Heinrich Duskfeather—figures who might be able to save Katerin from the brink of total desolation.

Will Katerin's last princess ever recover from the madness that plagues her? Or will the land continue its descent into oblivion under the rule of a broken monarch? Only time will tell.