In times of war, darkness finds a chance to strike. Once a lush and populous region of Valathe, Tenaerul was stricken by a deep arcane corruption in the wake of the Worldrend - supposedly caused by a shard of Terra Arcana slipping through the Gods' attempt to protect Istralar. The dark magic spread rapidly, forever altering the landscape. The sun's rays were blocked by a deep fog, and the natural flora of the region drank in twisted power to either change or perish. The towns and villages that lay within Tenaerul's borders had little time to evacuate, and not all inhabitants were able to flee before the fog spread to them. The Afflicted, as they became known all those years ago, live cursed lives. Unable to die through natural means, they linger in the world by the will of the magic flowing through their former homes. But it was not simply magic that tainted the area. As it spread, the corruption was enough to stir the Great Beast, Rovagug, from His prison. Though His power was restrained by the chains placed upon Him, the cancerous magic that ran through Tenaerul had no such restraint. It trickled through the earth to conduits of His power left within the planet millennia ago, and He seized the opportunity. The power wrenched through the planet, latching onto other lingering pockets of the Worldrend's magic, and the two events in concert served to spawn the Drow. Yet the tale does not end there. The dark powers at work served to attract countless demons and other foul entities from the Lower Planes to Tenaerul, and as the region grew, so too did their power. Those living in the many kingdoms nearby could only attempt to fend off the endless hordes - none of their attempts to permanently banish them, or to end the corruption, worked. Not until Ypolita, Champion of Iomedae, found out. Grieving for those lost and knowing her duty, Ypolita sacrificed herself in order to invoke the full breadth of Iomedae's protective powers. A shimmering dome of light surrounded the darkness, permanently sealing it. The cancerous spread had ended, and Valathe was no longer at risk. And so it remained, the tainted area marring every map, for thousands of years. Until Eskandar Nerezan. Until the Betrayal. Rovagug's destructive might split the shield, and only by the quick action of those who would form Celesthem Temple were able to prevent Tenaerul from resuming its corruption of life. But whilst their seal holds the barrier shut, the crack remains - granting any mortal brave enough the ability to enter. May the Gods help those foolish enough to do so.
Fauna & Flora
Though none have risked trying to measure exactly what life lingers within Tenaerul, the previously-mentioned Afflicted can still be found in the shattered remains of their former homes. Demons and other extraplanar monsters linger, often mocking guards of the shattered area with the bodies of former adventurers. Former wildlife seems to remain, but entirely changed - former songbirds twisted into winged abominations mocking the cries of the dead, for instance. The natural fauna of the region has also completely changed. Bushes bear strange fruits that glow in the darkness, and trees seem dead at a glance. Flowers give off strange fumes that impart feelings of lethargy and hopelessness, and small shrubs may either hold temptingly sweet berries - or deadly poisons disguised as such.