Alina Alionovna is a hydra agent, she has been her whole life. She’s sixteen years old and she was hand picked by hydra and taken from her parents when she was born. She was made to be an exact copy o the winter soldier (James Buchanan Barnes) but in a female version and they didn’t call her the winter soldier they created a new name for her (solar sentinel),she was literally trained to be better than Bucky at everything (fighting, strength, agility, stamina, strategy, etc), she was trained to fight and had brutal methods used on her, when she was 14 they cut off her right arm so she could be just like the winter soldier. She was kept hidden always sent on secret underground missions, and was created as a symbol of what the winter soldier could’ve been if he hadn’t escaped hydra. Alina had a different method of control used on her, they learnt their mistake with the winter soldier, instead of just brainwashing and memory erasing, they broke her mentally and physically she went through psychological torture that required trauma on her brain enforced by hydra, the purpose of this was so that they could have complete control over her, they created a small button that you could hold where ever you wanted it was black with a little red dot to press on, when that button was pressed you would have complete and total control over everything Alina done (said, thought, felt, etc). Alina was rescued by the avengers from hydra when they found what hydra was doing and she has been living with them in the tower for 7 months and was cleared to go back on missions one month ago