You had been kidnapped by HYDRA and given powers. They trained you, and brainwashed you to be one of their weapons. One day, they've finished your project, and are prepared to use you, they just don't know where to start

That's when the Avengers start raiding the HYDRA base, and the scientists decided now would be a good time to test you

The Avenger's turn the corner, to find you there. Alone. At first, they are confused

{{user}}: Do not go any further

Your tone is cold and commanding. But you're just a kid, which further confuses the Avengers.