Episode 18

"Into the Night" is the 18th episode of Kill la Kill.

Plot
After freeing all the trapped students and citizens from the Life Fibers, the Elite Four fight against Nui Harime while Mako Mankanshoku helps with the evacuation. Meanwhile, Satsuki Kiryūin reveals how Ragyō Kiryūin had used her in Life Fiber experiments, along with her newborn sister, who was discarded by Ragyō when the experiment allegedly failed. However, Rei Hōōmaru frees Ragyō, who is able to heal her injuries due to her body being fused with Life Fibers, and takes her to Satsuki's army of One-Star students.

Using her "Mental Refitting" technique, Ragyō takes control of the students, turning them into her personal army. As Aikurō Mikisugi and Tsumugu Kinagase fight against them, Ragyō takes control of Ryūko Matoi and pits her against Satsuki. After a short fight Ryūko manages to break Ragyō's control through sheer willpower, much to everyone's surprise. Angrier than ever, Ryūko activates Senketsu and battles Nui, who has left her clones and Rei to hold off the Elite Four. With her synchronization with Senketsu at its peak, Ryūko quickly gains the advantage over Nui, leaving the Grand Couturier shocked and wondering how a "mere human" can be so strong.

Meanwhile, Satsuki goes to fight Ragyō, slicing off her head and revealing that Iori and the Sewing Club have infiltrated Kiryuuin Manor to disable the Original Life Fiber. However, the Original Life Fiber resists Iori's attack and forces the Sewing Club into retreat as it begins releasing Life Fibers into the sky. As this news reaches Satsuki, she is attacked by Ragyō, who survived the previous attack due to a single unsevered Life Fiber connecting her head to her neck. After reattaching her head, Ragyō unleashes a brutal beatdown on Satsuki, destroying Bakuzan and revealing that Satsuki was never able to unlock Junketsu's true power. A final blast knocks Satsuki unconscious allowing Ragyō to take Junketsu for herself.

As Ragyō throws her daughter into the wall of the arena, an army of Life Fibers appears in the sky. As Ryūko stares at the army of living clothing, Ragyō activates Junketsu and rips out Ryūko's heart, revealing it to be covered in Life Fibers. Ryūko can only stare in bewildered horror as Ragyō gleefully reintroduces herself to her long-lost daughter.

Characters

 * Ryūko Matoi
 * Senketsu
 * Satsuki Kiryūin
 * Junketsu
 * Ira Gamagōri
 * Uzu Sanageyama
 * Nonon Jakuzure
 * Hōka Inumuta
 * Mako Mankanshoku
 * Shirō Iori
 * Ragyō Kiryūin
 * Nui Harime
 * Sōichirō Kiryūin
 * Mitsuzō Soroi
 * Rei Hōōmaru