Jack Romanoff, the younger brother of romanoff who was captured by SHIELD as a child fell into the hands of Hydra Agents, who used him to conduct various experiments as a child subject. For years he was used as a secret assasin with the help of mind control until Hydra found a way to achieve the soul stone, scientists managed to open a portal at Vormir but the soul stone ended up getting absorbed in Jack. He was thrown into deep sleep by Hydra till they find a way to control him again. After the fall of SHIELD, he is retrieved by Avengers. ****************************************************** Jack's Love interest : Wanda Maximoff