Satsuki Kiryuin Costume
You need the following items for your Satsuki Kiryuin Halloween costume:
How To Dress Like Satsuki Kiryuin From Kill la Kill

Dress like Satsuki Kiryuin from Kill la Kill;
Satsuki is a tall, slender woman with a square face resembling her mother's. She has thigh-length dark blue hair with set diamond bangs hanging over her forehead, blue eyes, rather thick eyebrows, and a fairly large bust. She has a habit of constantly frowning, although on rare occasions she does smile. Satsuki had long hair as a child, and while it was cut slightly shorter as a teenager, she later grew it out. In episode 25, as a page boy, she cuts her formerly long hair to shoulder length.
Satsuki Kiryuin Cosplay

Satsuki prides herself, to say the least, on being an extremely intelligent, calculating, and a patient young woman who is at once unflappable and ironclad. Unlike Ryūko and Senketsu, she was not ashamed to wear the Kamui Junketsu at its most revealing; She claims that as the Kamui's name suggests, their actions in applying junkets are "absolutely pure". Satsuki refers to humans as "pigs in human clothes" and justifies that the weak and stupid must be governed. Because of her unwavering faith, she also possesses natural charisma and the ability to lead others. Despite her pride, Satsuki proves pragmatic and determined, willing to put her pride aside and use any means necessary to achieve victory, even at the risk of her life. When Satsuki fought Ragyō Kiryūin, she realized that her willingness to fight her mother and the Life Fibers was due to revenge, and realized that great causes stemmed from personal desires.
Satsuki Kiryuin Halloween Costume
Despite her behavior at school, Satsuki is not heartless. Despite being very tough and not very willing to tolerate failure, she cares deeply for the Elite Four; and protects them as it protects them. As a child, she always drank Mitsuzō Soroi's tea to protect his feelings; Though she disliked its bitterness for a long time, she eventually found it delicious. Satsuki remembers Soroi and realizes that she must have been a kind-hearted girl, going so far as to protect her butler's feelings.
Satsuki really loved her father and sister enough to avenge them by attacking the mother she got rid of. Likewise, despite a bitter, almost hateful rivalry with Ryūko, Satsuki becomes noticeably softer on her for most of the series upon learning that Ryūko is the sister she had long thought dead.
After the final fight with Ragyō, Satsuki accompanied her younger sister on her date with Mako Mankanshoku and it is revealed that she has a hidden side of her personality that hasn't been revealed up to this point: she can be a bit shy and shy, eh seen in the pictures taken during the date.