Clockwork Vampire Chronicles

The land of Falanor is invaded by an albino army, the Army of Iron. A small group set off to warn the king: Kell, ancient hero; his granddaughter, Nienna and her friend, Katrina; and the ex-Sword Champion of King Leanoric, Saark, disgraced after his affair with the Queen.
Fighting their way south, betrayal follows battle follows deviation, and they are attacked from all quarters by deadly albino soldiers, monstrous harvesters who drain blood from their victims to feed their masters, and the twisted offspring of deviant vachine, the cankers.
As Falanor comes under heavy attack and crushing invasion, only then does Nienna learn the truth about grandfather Kell – that he is anything but a noble hero, anything but a Legend.