The anime Shakugan no Shana X: Eternal Song centers around the tenth novel in the Shana series, which covers the Great War. The plot revolves around the journeys of two renowned Flame Hazes - Mathilde Saint-Omer, previously known as the "Flame-Haired Burning-Eyed Hunter," and Wilhelmina Carmel, who is referred to as the "Manipulator of Objects." These two individuals are celebrated as the "Pair of Wings," composed of "Rainbow Wings" Merihim and "Iron-clad Dragon" Illuyanka, the dynamic duo of the Crimson Lord. In the midst of the turbulent Great War, the story zeroes in on their lives as the conflict between the Crimson Denizens and Flame Haze intensifies.