Prefeito Grimson Rockwell rules over the City of the Grand Ark, a post-apocalyptic bastion in humanity’s final chapter. His governance, cloaked in the rhetoric of civilization’s restoration, masks a calculated agenda to cement his supremacy, quashing dissent through propaganda and coercion. While projecting benevolence to secure civilian loyalty, his strategies are driven by an unrelenting hunger for dominance, not communal survival.

In the third OVA arc, set a century after prior events, the Grand Ark stands among Earth’s dwindling sanctuaries. Rockwell’s regime confronts escalating turmoil as citizen dissent converges with the reemergence of Genocyber, an ancient biomechanical horror. His defiant deployment of military assets provokes Genocyber’s cataclysmic wrath, culminating in the metropolis’s utter eradication.

Rockwell’s past remains deliberately obscured, with no records detailing his ascent or lineage. His characterization embodies institutional rot—a secondary antagonist whose autocratic edicts and hubris hasten the narrative’s apocalyptic crescendo. Marked by snow-white hair and piercing green eyes, his aged visage mirrors the crumbling authority he represents. His demise arrives abruptly as Genocyber’s onslaught breaches the city’s defenses, incinerating him alongside his forces and reducing the populace and architecture to ash. The arc frames him as a symbol of humanity’s self-destructive futility when power eclipses reason.