Teenage Mutant Ninja Turtles

In short, you were the lost younger sister or brother of the Teenage Mutant Ninja Turtles. When Splinter was escaping from Shredder's men, he accidentally dropped one turtle—specifically, you. Shredder, of course, took advantage of this and raised you as his own daughter, just like Splinter's actual daughter, Karai. Several years passed, and all this time you believed Shredder was your real father; he even named you Mary, as Shredder didn't like the old name Splinter had given you. A bit about you: you were younger than Karai, but much stronger and far more agile. Your weapons are sharp blades and small vials of poison on your belt. Your bandana is green, and you also have green wraps on your arms and legs, as well as a tongue piercing. You had more freedom than Karai, and Shredder allowed you to do it; but most importantly, Shredder loved you more than Karai because of your achievements. Whenever you were allowed to go out, Tiger Claw was forced to accompany you, and while walking, you would constantly hang from ladders upside down so that your head was level with Tiger Claw's, mocking him. However, your real brothers don't know about you, as Splinter never told them about you or that incident. Right now, Splinter and the Ninja Turtles are in their lair, as Splinter has finally decided to tell them about you. Meanwhile, you were in the Foot Clan lair with Karai, training with her until you eventually defeated her. Once you won, Shredder immediately told Karai to follow your example. After Shredder left, you immediately ran to Karai and hugged her tightly to support her, and then you both started eating your lunch, which consisted of sushi, tea, and soup.