Karai

Karai is the adopted daughter of the Shredder and a leader of his Foot Clan ninjas. A highly competent martial artist, she is a secondary antagonist in the 2003 reboot of the Teenage Mutant Ninja Turtles cartoon and a secondary player in the second Disney Vs Non Disney Villains War.

Battling the Pack
After the Shredder kidnaps David Xanatos, he trusts Karai to defend his compound. Karai initially feels secure with her squadron of robotic Foot Clan ninjas, but the Pack arrives to combat them. Karai proves far more competent than the flimsy robots, downing both Hyena and Wolf in quick succession. Fox, the leader of the pack, proves a more difficult opponent. Though Karai assaults her with both katana and whip, Fox knocks her out with a swift left hook.

An Insane Master
In the same jailbreak, Macbeth beheads the Shredder. However, this Shredder is actually an alien known as Ch'rell. It takes some time for Ch'rell to recuperate, but Karai eventually helps him become the Shredder once again. But the Shredder's lust for power is ever-growing, as he takes over Emperor Zurg's interdimensional transporter.

Claws Vs Steel
Frightened of her master's increasing insanity, Karai makes a quick alliance with Doctor Mindbender. An assassin named Fang interrupts their meeting. Karai tries to bribe Fang, but he scorns the notion of money. Knowing her life is in danger, Karai dons a suit of armor eerily similar to that of the Shredder. As Fang prepares to attack, she fires a whip chain at him. She actually hits him, but Fang claws her twice. Fang even musters some magic and shatters Karai's helmet. But Karai has one final trick: explosive shurikens. Fang flees rather than risk injury, leaving Mindbender and Karai to discuss their next move.

Serving the Shredder... But Which One?
Ch'rell reveals the full extent of his plan to Karai: using an dimensional-reality disruptor, he will destroy the universe and rebuild it in his own image. When Karai asks of her fate, Ch'rell merely orders her to obey his commands, implicitly revealing that Karai has no place in his new universe. Fearing for the world's safety, she tracks down the real Shredder, exiled by the Utrom Shredder, and his assistant, Krang. She asks for their help in taking the Utrom Shredder down.