The Demiurg are a mysterious and solitary Xenos race, previously virtually mythical to the adepts of the Imperium. In recent centuries, however, the vast, stately commerce ships of the Demiurg have become an increasingly regular sight in the Segmentum Tempestus, although they scrupulously avoid Imperial space unless specifically invited.
The Bastion-class vessel is perhaps a more common sight that the larger Stronghold-class, but are nevertheless only occasionally sighted in wilderness space. As warships, Bastions are comparable to Imperial Cruisers, possessed of impressive Lance batteries and turret firepower, although the Demiurg primarily use them for asteroid mining operations.
Pack of two resin ships. Full background and rules for this mysterious craft can be found in Battlefleet Gothic Armada. Master model by Sean Bullough