She wasn't like the others.
She had been created before them, captured at a young age, involuntarily. Like the first one.
She was much more rebellious than the others. Which they found inconvenient, but fixable. They took away her ability to speak. Her one freedom in the enslavement she landed herself in. And they named her Silent. A mockery.
They made her a weapon, a deadly assassin that could go toe-to-toe with the Winter Soldier. She was designed to be his partner, actually. They had made him a battering ram, the frontline assault. Silent was his backup. She was the rooftop sniper and stealth aspect of the partnership. Specifically made for the stealthiest missions HYDRA would ever need.
And they made her invisible, a master of camouflage, blending in. No one outside of HYDRA had ever known she existed, she was never seen on security cameras or by witnesses. If the Winter Soldier was a metaphorical ghost story, then she was the ghost story that ghosts told.
