Satsuki Kiryūin

"Fear is freedom! Subjugation is liberation! Contradiction is truth! Those are the facts of this world! And you will all surrender to them, you pigs in human clothing!"

- Satsuki addressing the students of Honnōji Academy

Satsuki Kiryūin is the president of Honnoji Academy's Student Council and the first antagonist in the anime Kill La Kill, but later becoming a deuteragonist after her plans to overthrow her mother's Life Fiber fashion industry came to fruition.

She is later revealed to be the sister of Ryūko and the two join forces in order to defeat Ragyo in the climactic battle against the Life Fibers, who sought to enslave and destroy the human race.

Appearance
Satsuki is a tall slim woman with an angular face similar to her mother's with long dark blue hair and blue eyes. She has rather thick eyebrows and a rather large bust. At the end of the series she cuts her formerly long hair to shoulder length in page boy style.

History
Satsuki was the first born child to Ragyō and Sōchirō Kiryūin, and soon became the first failed test subject of being fused with Life Fibers. However, after Sōichirō learned the truth about Ragyō, he knew that he would be punished if he betrayed her. He secretly taught a 5-year-old Satsuki about her mother and the secrets of Life Fibers. He then revealed that Junketsu will be her "wedding dress" before he took an infant Ryūko with him into hiding.

Personality
Satsuki is stubborn and arrogant, and rules over her school with an iron fist. At first, she seems to care little about those she deems benath her aside from the Student Council, and subjects them to harsh, even dangerous conditions. However, this is an extremist method to toughen the students up for the inevitable wars they will have to fight, though her rule still involves forces them into brutal discipline, squalorous conditions, and a fearful existance.

However, despite her apparent cold-heartedness, she is shown to occasionaly let her defenses down in the company of close friends and allies, where she will joke, converse, and bond with them. She trusts very few, but those she does trust see a more caring and approachable side, though she remains strict and arrogant.

Physical Prowess
Even as a child, Satsuki possessed enormous strength, able to take down 500 men and one-shot Ira Gamagōri despite his greater size and defenses. She is acrobatic and nimble, able to dodge incoming attacks and easily use kicks and punches to her advantage in combat. Her speed allows her to sprint extremely fast, and her reflexes allow her to quickly identify oncoming threats and react.

Intelligence
Satsuki is a master manipulator, orator, and liar. She can easily get others to do her bidding, whether they know it or not. She is strategic, and uses forethought and planning to carefully analyze opponents and either use them to her advantage or place them in seemingly unwinnable situations.

Bakuzan
Satsuki wields the Secret Sword Bakuzan, a black-bladed katana that she swings with massive force. The blade is incredibly sharp and durable, and is made of a material that is able to damage Life Fibers. This gives the weapon an advantage against Kamui, COVERS, and Life Fiber-infused beings. Bakuzan is powerful enough to go up against the Scissor Blades, but was shattered by Ragyō Kiryūin.

Bakuzan Gako & Bakuzan Kōryu
After Bakuzan was broken, two of its largest shards were forged into two new weapons, Bakuzan Gako and Bakuzan Kōryu, a long blade and short blade respectfully. These two swords possessed the same power as the original Bakuzan, but were able to be duel-wielded for additional damage and the ability to permanently sever Life Fibers.

Kamui Junketsu
Kamui Junketsu is a parasitic Kamui made by the Kiryūin family. When worn, Junketsu further enhances Satsuki's already great power, feeding off her blood to do so. Due to a lack of shame of its revealing nature, Satsuki was able to almost immediately attain the Life Fiber Override, propelling it into its most powerful form. While in this state, Satsuki's strength, speed, reflexes, and durability are enhanced tremendously, allowing her to move fater than the eye can see and strike with blows powerful enough to produce devastating shockwaves. However, due to her natural human resistance to Life Fibers, her synchronization with Janketsu is incomplete, meaning the true extent of her power cannot be accessed.

After her redemption, Junketsu was modified to contain both Satsuki and the Life Fiber-infused Ryūko's blood as well as fibers from Senketsu, Ryūko's Kamui. This gives her more access to Junketsu's abilities with less strain and effort.

Kamui Senketsu
For a brief time while Ryūko was brainwashed by Ragyō and was in possession of Junketsu, Satsuki reluctantly teams up and wears Senketsu. While the two are able to semi-synchronize, Satsuki is not able to gain full access to Senketsu's abilities, and is more working with Senketsu as partners as opposed to one being.

False Toenails
Two of Satsuki's toenails - her left and right big toenails - are actually false, made of the same material as Bakuzan, and sharpened to a point. Should she ever be caught without her weapons or a Kamui, she can use acrobatics to strike enemies with her bladed feet. Due to their material and sharpness, they are effective against Life Fibers.

Trivia

 * Episode 1: Satsuki's "facts of this world" are heavily inspired by George Orwell's most famous novel, Nineteen Eighty-Four. In the novel, the Party's slogans—"War is Peace", "Freedom is Slavery", and "Ignorance is Strength"—were paradoxical statements that held hidden truths about the world in the novel. Satsuki's "facts of this world" speech, coupled with Ira's execution of the Goku Uniform thief, were intentionally chosen to introduce her as a ruthless dictator.