The Lightbringer Series by Oliver Johnson

It is a time of great darkness, when the sun is in danger of being forever extinguished, and mankind has been divided into two warring factions: the worshipers of the God of Light and the servants of Eternal Night. Now three unsuspecting travelers are called by prophecy to face a legion of the undead and the powers of the Dark Lord in the faint hope of reclaiming the world for the light.

In this, the second book of the epic trilogy begun in THE FORGING OF THE SHADOWS, the once-glorious city of Thrull has become a place of death and despair. Seven years before, Lord Faran Groton, High Priest of the God of Darkness, overthrew Thrull and set loose his army of vampires to plague the city, waiting for the day the sun would rise no more... But the God of Light has his champions as well. A motley trio of survivors searches for the three ancient artifacts which can defeat the darkness... moreIn this, the second book of the epic trilogy begun in THE FORGING OF THE SHADOWS, the once-glorious city of Thrull has become a place of death and despair. Seven years before, Lord Faran Groton, High Priest of the God of Darkness, overthrew Thrull and set loose his army of vampires to plague the city, waiting for the day the sun would rise no more... But the God of Light has his champions as well. A motley trio of survivors searches for the three ancient artifacts which can defeat the darkness. Traveling far beyond their own lands, they will encounter nightmares and disasters before facing their most dangerous enemies--the Dark-born Nations of the Night! less

With the sun's light waning, humankind has divided itself into the worshippers of the God of Light and the servants of Eternal Night, with both factions preparing to do battle to the death, in the epic conclusion of The Lightbringer trilogy.