The Tesseract Vault is a masterwork of Necron engineering, a colossal drifting construct built to cage the incalculable power of a bound star-god. Where a mere prison holds a C'tan Shard in dormancy, the Vault is a weapon: it draws upon its captive's essence and hurls that stolen divinity across the battlefield in cataclysmic arcs of force. It floats above the ranks of the Necrons like a black cathedral of geometries the mind refuses to hold.
Within its shifting walls, a shard of a shattered god rages in eternal captivity, its power tapped and channelled by crypteks who understand the terrible risk they court. The Vault can hurl transdimensional lightning, wither armies to dust, and shrug off firepower that would gut a battleship. To face one is to war against a piece of divinity worn as a machine.
Yet the Vault is more than an engine of war; it is a symbol of the Necrons' ultimate triumph and their ultimate arrogance. They took gods and made them slaves, and they parade that conquest across the stars. Should the containment ever fail, the imprisoned shard would burst free with an appetite unbound by ten thousand years of confinement. The deathless know this, and still they deploy the Vault, trusting cold logic and ancient wards to keep the caged god from remembering how to be free.