Bastard sword, one of 10, with powers of light, created to hunt undead.
Ten of these hand-and-a-half swords were forged by Elverandil for the bane of the undead.
A Blade of the Sun is able to channel the light of the Sun itself, and use this positive energy to destroy the undead.
Sack's Blade had lain in the tomb of Daltin Kotessė in Gorntar Castle for 800 years when he found it. It has since been blessed by the combined gratitude of the Gods and it's powers greatly increased, making it a unique item.