Spiral: The Bonds of Reasoning Vol 9

From the Yen Press edition

Kanon is startled by the sudden arrival of Madoka Narumi, but not so much as to shake his aggressive offense. Still, it's enough to give Rio the chance to rescue the captive Ayumu. Free at last, Ayumu must face the difficult decision that lies before him. Is his only option to kill Kanon? As the Blade Children fall back and lick their wounds, Ayumu must find a solution to end Kanon's reign of terror once and for all, even if it means becoming a murderer himself.

Source: Yen Press