Fate/kaleid liner PrismaIllya Movie: Licht - Namae no Nai Shoujo

The world is dying, no longer able to support life. The Ainsworth family can use the Holy Grail to save humanity, but the price of salvation is sacrifice of the magical girl Miyu but Miyus brother, Shirou, wont let them have her without a fight. Now its up to Illya to step in and find a solution that will save not only Miyu, but the entire world for impending doom. But when the price for the world's salvation is the life of a single, innocent girl, what will Illya choose?