TV Special
Description
Leonardo Bistario Harwey, heir to the Harwey dynasty controlling sixty percent of global wealth, was born from the union between the family's former patriarch and his mother Alicia. From age three, he endured surgical and thaumaturgic enhancements that implanted knowledge directly into his consciousness, molding him into a perfected ruler. His half-brother Julius B. Harwey, judged unfit for leadership, later received orders to assassinate Alicia, removing obstacles to Leo's succession.

As a Master in the Moon Cell Holy Grail War, Leo summoned Saber-class Servant Gawain while openly flaunting his identity. His crusade stemmed from the conviction that unrestricted Grail access would spark worldwide warfare; he aimed to claim its power to enforce lasting stability under Harwey rule, favoring sustained equilibrium over abrupt societal shifts. Raised without ordinary human emotions and conditioned for invincibility, he deemed failure impossible until defeated by Hakuno Kishinami—an event that plunged him into despair and shattered his worldview's foundations.

During *Fate/EXTRA CCC*'s Far Side incident, Leo defied memory seals and BB's influence to retain Gawain. Assuming student council presidency, he adopted a carefree, childish persona contrasting his regal stature. Facing BB's threat, he consumed every Command Spell to sever his contract with Gawain, sacrificing his life to block the Servant's absorption. This sacrifice transferred authority to Hakuno, symbolizing Leo's embrace of imperfection and a fleeting glimpse of ordinary existence.

In *Fate/EXTRA Last Encore*, centuries post-defeat, Leo's consciousness persisted through Twice H. Pieceman's machinations. Embracing Twice's ideology, he championed erasing human history to end cyclical suffering, emerging as an antagonist incarnating stagnation. His final clash with Hakuno highlighted his shift from a control-obsessed ruler to a prophet of annihilation consumed by nihilism.

Leo's philosophy, dubbed the "thorough ideal," sought to forge a society where unequal beings coexisted as equals by shedding personal sentiments while preserving core humanity. His regal charisma compelled allegiance, though his aura evoked primal discomfort. Interactions with artificial entities like Sakura Matou and Rani VIII featured detached recognition, acknowledging their roles within his structured worldview.

His form shifted across incarnations: a youthful orange-clad student avatar during the Near Side, a black-uniformed emblem of unity in the Far Side, and an older trenchcoat-adorned manifestation in *Last Encore*. These transformations mirrored his metamorphosis from ambitious heir to self-sacrificing authority, culminating in an omen of mankind's extinction.