Miles Byron emerged from a lineage of medical practitioners, initially operating a clinic where treating patients and earning community gratitude brought fulfillment. When the Patrian civil war erupted, he enlisted as an army medic to aid wounded soldiers. Witnessing high mortality rates among his patients bred profound distress, seeding doubts about his purpose and effectiveness. This disillusionment drove him to volunteer for the Incarnate program, seeking direct influence over battlefield survival.

Transformed into a Centaurus Incarnate, Miles gained a hybrid physique—a human torso fused seamlessly to an equine lower body, towering 13 feet tall. This form endowed him with immense strength, battlefield agility, accelerated regenerative healing granting near-immortality post-war, and heightened stamina. He merged traditional weaponry with these enhancements: impaling foes at close range with a large spear and executing daylight-perfect long-range kills via a customized oversized bow. He notably avoided firearms entirely.

Post-transformation eroded Miles’s once-compassionate nature. He began deriving explicit pleasure from victims’ terror upon encountering his Incarnate form, rationalizing that fear or gratitude now defined his existence regardless of action. Despite this moral decay, he retained medical expertise, continuing to treat injured soldiers at Bold Creek Fort—a stark duality in his character.

Under Cain Madhouse’s command in the Free Nation of New Patria, Miles executed a lethal strategy against government scouts near Bold Creek, eliminating reconnaissance teams with precision archery. When the military unit Coup de Grace attacked at night, his visual limitations in darkness reduced his effectiveness. Enraged, he charged as "Death" with his spear, confronting former comrade Hank Henriette—now a Beast Hunter—and questioning Hank’s resolve to kill allies before retreating.

The final clash unfolded during Coup de Grace’s full assault on Bold Creek Fort. Miles alternated between archery, spear combat, and grenade throws into trenches. Hank exploited rain-softened mud to immobilize him, enabling soldiers to bombard Miles with Alphahard—a corrosive toxin derived from Hydra Incarnates. As the poison dissolved his body, Miles voiced regret over wartime choices and mourned his corrupted self, lamenting dying in agony rather than gratitude. He condemned military exploitation of Incarnate corpses before Hank delivered a terminal Godkiller bullet. With death imminent, Miles bade Hank farewell, wishing to reunite with fallen comrades once Hank had "played" sufficiently with Cain.

Mythologically, Miles paralleled Chiron—the centaur healer of Greek lore—sharing a medicinal background and a death linked to Hydra-borne toxins.