Long have the Thornspeakers struggled against such magics. It is a conflict as old as the Drust themselves.
Gorak Tul's influence, however, has vastly shifted the balance toward that of decay and death. It corrupts what would be an ordinary curse.
I believe Ulfar can correct this.
Go into Gol Koval. Slay our enemies, destroy their cairns, and collect their magics into this vessel.
With it, Ulfar may be able to find a way to cleanse your materials.