"Lord Kelvyn's Bulwark" from Battlehorn Castle DLC. Found in the chest at the foot of the player's bed. It has the same pattern as the one for Lord Kain's shield as well, found at the foot of the gate entrance to the castle next to his body.
It's the sword you get for clearing Xedilian for Sheogorath in the Shivering Isles expansion pack. Switches between Dawnguard and Duskguard depending on the time of the day.
7 comments
I tried to get money off hunting the first time I played (no mods), and was so sad when I realized it was worthless... thanks