Karai

Background
Karai is Shredder's adoptive daughter and one of his greatest followers. Shredder taught her Bushido when she was younger, and taught her the ways of Ninjutsu. Karai was exceptionally gifted in deception and was considered a master by Shredder.

New York
At somepoint she came to New York to help her father with his revenge against Hamato Yoshi. At somepoint she met Leonardo who was talking to himself, and was able to ambush him with her agility and blinding powder. Considering Leo amusing and not as boring as other opponents. While she is exeptionally skilled in the Art of Deception; she was also exceptionally skilled in Taijutsu and Kenjutsu. However, the friendship ended after the Turtles betrayed her to get to Splinter after agreeing to work together to stop the Kraang. At somepoint she tried to kidnap April O'Neil; however she was beaten after April mentioned she lost her mother. This caused Karai to become off balance. This allowed April to throw her down a flight of stairs.