Shakugan no Shana X: Eternal Song IV is the fourth volume of Shii Kiya's manga based on the tenth light novel volume of the Shakugan no Shana series. It was released simultaneously with the fifth volume.
Publisher's Summary[]
Feelings towards the ones who must be defeated, and where those feelings lead——
Mathilde and Wilhelmina rush into battle against their archenemies, the "Pair of Wings" Merihim and Illuyanka!! It becomes a desperate struggle as each person's mission and feelings intersect——[1]