Magical Girl Apocalypse Vol. 5 (manga)

Amidst the devastation of a post-magical girl world, Kogami Kii and his companions find themselves crossing paths at the university hospital. Seriously injured, Akuta hatches a plan to eliminate all of the magical girls at once, but it will take a lot of luck and a little time travel. Meanwhile, Kii awakens to find a mysterious letter in his hand and a gift that will shake the world to its core. Blood will be spilled as a final confrontation between Akuta, Kii and Tsukune's alternative personality, Asuka, draws near. Is there any chance of a "happy ending" for Kii and his friends in this hopeless world?