Disaster / Destruction
The Tearing (also known as the Unraveling) is the moment when the Veil that surrounds the Material Plane became so weak that the most powerful outer planar beings, the Nihilan Lords, were able to enter the Material Plane with impunity. It is uncertain what transpired, but it resulted in the Great Scar forming across the South eastern side of Munhart, and the end of the People of El-Han. It’s results allowed for an outpouring of Astral Creatures (Celestials, Fiend, Aberrations) into the Material Plane.
The Tearing is a cataclysmic event that permanately altered the world of Mundus forever. No one knows what caused it to happen apart form the fact the Veil was left weakened. There are constant debates over who was responsible for weakening the Veil, with some blaming a wizard known as Hesil Cevan.
The Tearing began in proper when the Nihilan Lord known as the Calamity was able to invade the Material Plane with an army of powerful demons. Following after him, other Nihilan Lords such as the Tormentor, the Revel King, and the Infernal Sovreign also began to make their way into this newly opened plane of existence. Seeing the new foothold that their eternal foe was able to make, the Celestials dwelling in the Aether began to invade as well, resulting in a brutal worldwide conflict that lasted for centuries, decimating the population of Mundus. Much of this era remains shrouded in mystery, with very little historical data remaining apart from various legends and myths, but the Land of Whispers is said to have been a direct result of the fallout of this war.
This era ended when the new Greatwyrms, the Aetherians, and a group of mortal wizards known as the Septimus Arcanus, were able to repair the Veil. The Veil is not as powerful as the first one, so while the Nihilan Lords and Archfiends are unable to travel between the planes, lower level beings can access the cosmos under the right conditions.