The Unmaker

The Unmaker, the 10th Power of The Powers which controls the ability to unmake reality, causing things to not only cease to exist but to have never existed in the first place. When the Unmaker deigned to destroy the world, the other nine Powers imprisoned it within Cloudmourne.
However, no prison can keep a God and slowly, despite their best efforts, the prison built by The Powers that holds the Unmaker begins to break apart. Led by it's agents The Blight spreads slowly southwards, unmaking all that it touches. Monstrosities and other twisted perversions issue outwards of the black morass, corrupting and destroying those few who still protect the realm against it's influence.
Alongside of this twisted agents and the cult of unmaking, The Voices of the Dark work tirelessly to hasten the inevitable end of the world. The extent to which The Unmaker is free is uncertain, but the time will come when it once again breaks free, and if the Dragons and Elf empires could not stand against it, how can those that barely survived? Something most be done, but when faced with such a threat, one that could challenge the other Nine, what possible thing could be accomplished?
The Black Shard is the central piece of the once obsidian stone which was a key created by Darkblade; a Shade, to free the Unmaker from his prison plane. However when it shattered the smaller pieces were displaced, and have been scattered around the world.