The Blackspire

The Blackspire is a legendary magical monument, located in the far north of Tyrrus. It was originally designed by Nekrus the Runic King and his apprentice Zaikerik, and built by a legion of workers, wizards, and rune-smiths. It is an immense tower of sheer black stone, covered in intricate runes. A steep and narrow staircase winds around the outside. While it was complete, it was the tallest structure in Tyrrus, and perhaps all of Coryphiel.
The Blackspire is built on a very specific and very important location, it is built far away from the Skyspires, but also equilaterally between them. It is designed to disrupt their network of power, and one who controls the Blackspire can control the structure of the realms themselves.
After its creation, the Blackspire was immediately used to break the First Veil, the barrier between the mortal realm and the Spirit Realm. This caused lost souls to wander into the mortal realm, and allowed for the use of Death Magic. Shortly after this, however, it was destroyed by Velkyn before it could do any more damage. Zaikerik built the settlement of Mortholme around the fallen Blackspire, and began to study necromancy.
Many centuries later, long after his death, Zaikerik began plotting to rebuild the blackspire, and use it for a new ambition. He created the Cult of the Blackspire, mortal followers who had studied the teachings of Zaikerik and Nekrus, recovered from Mortholme and Runeholt. Construction began in 19.80, and the Blackspire was fully reconstructed in the winter of 20.18. Just as Zaikerik was about to use it to restructure the realms once more, the Saviours arrived, carried by Velkyn, and defeated him. After this, Velkyn once more destroyed the Blackspire.
The ruins of the Blackspire are guarded by undead warriors, Knights of Velkyn, lest anyone attempt to rebuild it again.