Shadows Fall. The Shadow Trilogy, #3

The kingdom of Tar Ebon burns. They are called the Krai'kesh, and they are not of this world. They came from the far north, crushing our mightiest fortress and slaughtering our army. Creatures of claws, pincers and endless malice, they ravage the land and seek to destroy our most wondrous city. As the war flares, as the Krai'kesh threaten to overrun the capital city of Tar Ebon, seven heroes of might and magic go forth to unite the nations under a single banner.
Their next battle must be fought together or shadow will swallow all. The Krai'kesh will not rest until the last human is dead. John and his allies must defeat them. They must win. Or Tar Ebon, and, in time all humanity, will perish.