Just over a millennia ago the goddess of darkness, Nyx, had sufficient power to break through the veil of between her realm and the world of Valeria. As the veil dissipated her massive army of spectres, corrupted humans and elves, and demons poured into Valeria. Like a deadly plague everything that the Nyxians touched became diseased and withered. The worlds had begun to merge, the sky darkened and Valeria was thrown into complete darkness, there seemed to be no limit to Nyx's power and no way to stop her.
Old treaties were called upon and an emergency council was formed. The council pulled together all of its resources and launched an all out defensive against the invasion. Many lives were lost in this offensive, especially during the initial conflict, however through tireless fighting and continuing resources from all races the Nyxians were overcome. Nyx, fuelled by the despair of the people of Valeria, kept generating more spectres and demons. The only way to defeat the invasion was to overpower Nyx and force her back into her realm.
Whilst all available warriors fought the Nyxians, every mage and priest with even the tiniest magical ability were called to Iona, the capital of Valeria, to comit their energy to raising enough magic to repel Nyx and reinforce the veil between the two worlds. This seemed like a futile effort and many exhausted even their own life energy for the cause, with the arrival of draconians the magical energy grew greater than Nyx's power. A grand ritual was performed to bind Nyx's powers and banish her back into her own realm. The veil between the worlds was then reinforced with numerous barrier spells and the remaining Nyxians were defeated.
The veil since then has been weakening and Nyx's power is once again increasing. Another invasion seems inevitable, but only time will tell when it happens and how it ends.