Kara is located in the Hidden Chamber of Odin within the River Pass area. As with the other Valkyries, the Magic Chisel is necessary to open the chamber. Kara is unique in that she can summon Draugr to aid her in combat. Focus on eliminating the Draugr swiftly while avoiding Kara's ranged and close-quarters attacks. Using Atreus' arrows to interrupt her summoning will make the fight more manageable.