The fortified obsidian spire on the eastern Varnhalt Frontier — smooth, seamless, casting neither light nor shadow. The Black Stone Tower repels the Fray for a measurable distance around itself, creating an island of stability that local geography slowly reorganises itself around. Sera built her settlement here and exploited the Tower's field to bind a population of dependent followers; Rook and his bonded Servine Myx broke that arrangement, the Tower cracked open, and the third Shard of the Pattern was recovered from inside. The structure still stands and still repels the Fray, though more weakly than before. Vaultkeepers consider it the last intact Rogue Architect work outside the deep Glass Expanse.

No stories reference this entity yet. This part of the world awaits its chronicler.