Complex sentence: In Norse mythology, Herja (Old Norse) is a valkyrie attested in the longer of the two "Nafnaþulur" lists found in the "Prose Edda".
Split into simpler sentences: In Norse mythology, Herja (Old Norse) is a valkyrie. Herja is attested in the longer of the two "Nafnaþulur" lists found in the "Prose Edda".