Sunder is a legendary hammer crafted by the Dwemer Tonal Architect Lord Kagrenac. Together with Keening and Wraithguard, these tools are necessary to handle the Heart of Lorkhan. All three artifacts came into the possession of the Almsivi following the Battle of Red Mountain. Sunder, along with Keening, was subsequently lost during an annual pilgrimage to the Heart, sometime in the Third Era.
*inserts coin*
