Nibelung is the strongest dragon to have ever lived in the Old World that existed before Teyvat. He was the leader of the seven Dragon Sovereigns, and is considered a historical figure in Teyvat who was killed in the war with the Heavenly Principles after acquiring forbidden knowledge, becoming corrupted by it. Nibelung is characterized by a deep sense of justice for his kind, the Dragons and Vishaps, willing to pay any price in blood and steel to reclaim the lost glory of the dragons.