Revelation spheres take up an entire square as blocking terrain. Each revelation sphere radiates a continual 20-square close burst. Powers with the illusion keyword can’t be used within the burst and powers with the illusion keyword end upon entering the area of the burst.
Invented well after the city of Mithrendain grew beyond the bounds of the original fortress, revelation spheres are solid marble spheres roughly 8 feet in diameter set into the indentations in the ground. Each revelation sphere is covered in glowing runes that pulse with arcane energy; these runes cause the spheres to give off waves of magical energy that disrupt illusions, including invisibility. In the Feywild, invisible threats pose extreme danger, since they could otherwise walk directly to the center of the city; given the number of creatures in the Feywild capable of turning invisible, it is no wonder the city’s leaders ensured that revelation spheres were placed at intervals throughout the city, ensuring that their zones of influence overlapped to cover almost the entire city.