Legacy of Ruin

Before you can take the Seal to Captain Steinhauer, you must prove its authenticity. As you know there are a number of Dark Elves arriving in these lands to assist the forces of Chaos and bring down our Empire. Take the Seal to the nearest group of Chaos Warriors, find a Dark Elf named Rathaur, and attack him with it. It is believed that the Seal will kill any Dark Elf immediately. If Rathaur falls instantly, we will know the Seal is legitimate, and you can take it to Captain Steinhauer.

Search for the Shadow Outlaws' camp in the swamps south of Hochnar. Locate the Dark Elf Rathaur and use the seal to weaken him, and then kill him. Return to Captain Tobias Steinhauer in Lissariel's Shade at Kraussner's Garrison when done.