The Seat of Shadows is the palace of the Ashen Lady, head of the Iron Legion of Stygia. From the Seat of Shadows, the Ashen Lady and the Iron Legion oversee their part of the Hierarchy by building and reinforcing Stygia and its Necropoli's defenses.

The Seat of Shadows stands out on the skyline of Stygia. Massive black towers topped with white spindles jut through the air above the Isle of Sorrows, giving the Seat the appearance of a massive insect stuck among the city. Like many buildings in Stygia, a closer look reveals that several fragments of architecture from different time periods are used in its construction. The building is one of the largest in Stygia, even rivaling (though not topping) the Onyx Tower. In addition to its enormous structure, its appearance changes throughout the day. In the morning it appears bright and new, as if it were just completed. As the day wears on, the building begins to age and crumble; by the end of the day, it looks decayed and decrepit. The constant change of its appearance serves to remind the Iron Legion (and perhaps other wraiths) that nothing can escape the grasp of time.

Within are quarters for the members of the Legion, numbering in the thousands. The Ashen Lady's living quarters are also located here, as well as the quarters for the Council of Ministers, the Salon, and the their bodyguards. Also housed within this massive facility are a private library, research libraries, drilling and training grounds, priceless works of art, and the reliquary which holds thousands upon thousands of relics.

The Seat of Shadows can be toured, but access is strictly limited to those outside of the Iron Legion.