Roswaal L. Mathers reigns as lord of the Roswaal Mansion and the 12th successor of the Mathers lineage, his striking visage marked by navy-blue hair, mismatched golden and azure eyes, and theatrical face paint. Though occupying a host body aged in its thirties or forties, his soul persists across four centuries through a hereditary ritual pioneered by the original Roswaal A. Mathers—Echidna’s protégé, who first bound the family’s fate to the Witch of Greed. Obsessed with resurrecting her sealed soul, he perpetuates his existence by leaping between descendants, each lifetime dedicated to dismantling the barriers imprisoning Echidna within her tomb.
To reclaim his mentor, he has spent ages excavating arcane secrets from her forbidden archives, engineering political upheavals, and coldly maneuvering allies and enemies alike. He salvaged the Oni twins Rem and Ram from their razed village, molding them into loyal maids while withholding genuine attachment, their utility secondary to his ambitions. His plots weave through generations, employing assassins like Elsa Granhiert to provoke chaos and exploiting Subaru Natsuki’s time-looping curse to steer Emilia’s rise to power—a calculated step toward procuring the dragon’s blood required to breach Echidna’s prison.
Gifted with the Divine Protection of Sorcery, he commands all six elemental magics, solidifying his reputation as the kingdom’s apex combat mage. Physical prowess fluctuates between host bodies; predecessors such as Roswaal J. Mathers honed martial mastery, while his current form prioritizes strategic calculus over brute force. He dissects battles through probabilities, readily trading lives for advantage, and counters threats like Vollachia’s Magical Sharpshooter Balleroy Temeglyph by forging alliances to offset his mobility constraints.
His rapport with Beatrice, fellow inheritor of Echidna’s legacy, frays under the weight of manipulation, yet flickers of kinship linger beneath their transactional exchanges. Though he masks vulnerability behind eccentricity and logic, fleeting glimpses of isolation emerge when discussing magic’s mysteries—echoes of an ancient yearning that fuels his relentless schemes. From rigging sanctuary trials to igniting continental wars, every machination serves his singular fixation: defying death itself to reunite with the witch who once defined his purpose.