OVA
Description
Cecilia stands as the central antagonist throughout all official Murder Princess narratives. Her origins lie in the old world, where she acquired access to lost technology forming the foundation of her formidable abilities. Defined as a powerful sorceress, her magic flows through specific artifacts: a unique jewel embedded below her neck and a baton. She channels energy via the chest jewel to cast spells, wielding lightning projection as her primary offensive weapon. Additional capabilities include generating purple flames around her hands and erecting potent defensive barriers. This vital jewel regulates her power and constitutes her sole physical vulnerability. Its loss renders her energy uncontrollable, inevitably leading to catastrophic results for her.

She exhibits a personality marked by detached cruelty and manipulation, displaying absolute absence of remorse for her actions. Cecilia views immense power as its own justification. Her singular motivation is the relentless acquisition of greater power, specifically the pursuit of the legendary force Teoria, which she believes would grant her unlimited control. This quest drives her to orchestrate events from the shadows, manipulating key figures like Dr. Akamashi and Prince Kaito. She exploits Akamashi's scientific ambitions concerning lost technology to instigate a coup in the Forland Kingdom, aiming to access Teoria sealed within its castle. Later, she corrupts Prince Kaito, twisting his disillusionment with humanity's wars into a desire to wield Teoria for global destruction, positioning him as her enforcer, the Black Knight.

A defining element of her backstory involves Falis. Years prior to the main events, Cecilia annihilated Falis's village and slaughtered its inhabitants, including Falis's parents. This act held no strategic purpose; she targeted the settlement merely due to its convenient location, allowing her to test her powers' limits. Cecilia explicitly states this callous rationale when confronted by Falis, embodying her belief that "great power is for great people to use" and that lesser lives are expendable for her whims. This traumatic event cemented Cecilia as Falis's lifelong nemesis.

Cecilia's schemes culminate during the Forland succession crisis. Following Kaito's return, she infiltrates the castle under a hooded guise to locate Teoria's sealed chamber. Her identity is revealed during a confrontation, where Falis recognizes her as the destroyer of her village and attacks. Protected by the brainwashed Kaito, Cecilia overpowers Falis and orchestrates the expulsion of Falis and her allies from the kingdom, enabling Kaito's coronation and advancing her plan to unlock Teoria.

Her defeat occurs in the final confrontation. Falis shatters Cecilia's necklace, exposing the vital jewel on her chest. A precise strike from Falis's katana destroys this jewel. Deprived of its regulating function, Cecilia's accumulated power violently destabilizes, resulting in her instantaneous vaporization in a blast of purple light. This destruction halts her quest for Teoria and eliminates her threat permanently.