Demonstorm - James Barclay (First edition)

This is the end...

The dragons have gone home, the elves are safe. The Raven have kept their promises. But fate has not finished with them.

As the war between the colleges rages on, an old enemy senses that his chance to avenge a bitter defeat has come. Tessaya, Lord of the Paleon Tribes, has waited patiently for his moment and now, with Balaia in flames, he makes his move and unleashes the Wesmen hordes.

In Xetesk, his forces scattered, Dystran, Lord of the Mount, faces certain defeat by the Wesmen unless he unleashes the horrifying power of dimensional magics. And Dystran has not come this far to be beaten at the last by a rabble of ignorant tribesmen. And so the veil between dimensions is torn...

And beyond, a predatory evil stirs. Demons catch the scent of countless souls in Balaia. 

Can even The Raven prevail when the world is coming to an end?