Sadi

Sadi-chan is the chief guard of Impel Down. Her name comes from the word sadism. Due to the "-chan" part of her name coincides with the Japanese honorific, people tend to mistake it as such.

Appearance
Sadi-chan resembles a dominatrix in design. She dresses in a very skimpy devil-themed outfit. She carries around a pitchfork and wears a headpiece that resembles horns. She has long hair that covers her eyes. She also wears candle-shaped earrings.

Personality
As her name suggests, Sadi-chan is a sadistic person who enjoys bringing pain and torture to others, including Marine allies, and can't seem to get enough of their screams. She also seems to have extreme pride in the virtually perfect defenses of Impel Down, and refuses the assistance of the Marines.

She also tends to add an "mmmmm--!?" in the middle of her sentences, and insists to be addressed as "Sadi-chan", which is to correct people in case they think the "-chan" is an honorific (which is not, but is part of her name).

Abilities and Powers
Sadi-chan is a chief guard of Impel Down with some authority over lower ranking subordinates. She appears to be in command over the Four Demon Guards.

The pitchfork she carries around conceals a custom-designed whip which she can use quite adeptly. She also fairly strong in her own right, taking out a section of the bridge over the Pool of Blood during Luffy and Iwa's mass break out.

History
Sadi-chan was first seen standing outside the gates of Impel Down, refusing the assistance of the Marines in capturing Luffy. She was later assigned to guard the entrance to Level 5, where Magellan deduced Luffy will head, along with the three of the Demon Guards (she was shocked that Minotaurus was defeated).

She was then seen serving sake to the three Demon Guards, waiting. After Luffy was captured, she was in Level 3, ordering the Demon Guards, as well as the other guards, to hunt for Mr. 2 Bon Kurei, who they were unaware slipped into Level 5. Sadi-chan became very angry when the three Demon Guards cannot find Mr. 2 Bon Kurei anywhere on Level 3, and whipped them hard for it.

After Luffy, Ivankov, Inazuma, Jimbei and Crocodile escaped from level 6, she was ordered by Hannyabal to go down to level 4 to fight them. She is seen with the other guards showing shock after Luffy, Jimbei and Crocodile defeated all three Demon Guards.

Trivia

 * She is the second character to have a Japanese honorific problem with the word "Chan" in the name, the first being Hatchan who caused fan confusion over whether or not his name was a honorific.