Shakugan no Shana X Eternal Song: Harukanaru Uta

This story is based on the tenth novel in the Shana series and centers on the Great War. It follows two notable Flame Haze, Mathilde Saint-Omer and Wilhelmina Carmel, who are known as the counterparts to the Crimson Lord duo "Rainbow Wings" Merihim and "Iron-clad Dragon" Illuyanka. The narrative begins during the height of the Great War, a time of intense conflict between the Crimson Denizens and the Flame Haze. The two Flame Haze are depicted as significant figures amid the turmoil, with their roles and experiences highlighted throughout the events of the war.