The Enchiridion of the Silver Void

Discovered in Flamerule 1495 DR, the tome seems to be Elvish design and some of the typography written in an Elvish script. Found in a Kobold Lair where both magical and scientific experimentations seemed to have taken place. 
With a quick turning of pages, it was uncovered that there was once a powerful spell-caster by the name of Varal, a mage of great power who was able to conjure silver gateways to rid the lands of fiends into a demi-plane of his own creation, which was aptly named the Silver Void.
== Research ==
==== Undertaken by Lost Flame - Hammer 1496 DR ====
A week of pouring through the Silver Void, the Tabaxi discovered that this famous mage, Varal, was of Drow descent, but was not a follower of the Spider Queen, having rejected the den that he come from in the underdark and sought out the teaching of Elysian Institute of Arcana.
It also read, that Varal had such knowledge, that he had even crafted and composed his own spells as he was able to bend the weave to his will unlike any other before him.
The Silver Void is an incredibly high level spell with influences of plane shift, arcane gate and the banishment spell. Currently a horde of demons in their thousands currently exist in a demi-plane of his own creation, awaiting their return to the material plane where they wreak havoc upon Elysia once more.
Varal notes that whilst he does no fear the power of a demon Lord, knowing that he would be capable to ridding the world of it with a casting of Silver Void, if the four Demon Lords were released, then their power would be enough to undo what he done to their horde.
It is also recorded that the same spell was attempted on the Mindflayers and their spelljammers, but their ability to planeshift abilities enhances by psionic powers was enough to easily escape the Silver Void. Hence Varal came to accept their arrival, and was forced to merely hide in his tower as the world around him was slowly destroyed and lost to decay as the population of Elysia were imprisoned, indentured, and consumed, otherwise taken to other planes on passage upon the Spelljammers slave ships.