Agathon

This high-confidence Gothic Sector pin is the map's Agathon, the hive-and-fortress world that garrisons more than ten million Imperial Guard and anchored the Agathean Domain in the Coronid Deeps beside Port Maw. Crusade fleets and the MaSade rogue traders brought it in; a Heresy coup kept it loyal while the Coronid fighting bled it. Named Gothic War battles for Agathon itself are not in the BFG timeline, so this overlay does not invent a Blackstone or Planet Killer scene.