In the Rasputin story, Rasputin was a self - styled holy man. He came from a humble background but managed to worm his way into the inner circle of the Russian royalty. He was believed by some to have healing abilities which is what initially attracted the attention of the Tsarina, who was desperate to find a cure for her son's illness. However, his unorthodox behavior and the influence he exerted over the Tsarina made him a polarizing figure in the court and in Russian society at large.
He could interact in a protective way. For example, if it's a small animal like a rabbit, he might build a safe place for it. His military training would make him good at creating a secure environment.
For 'dark winter soldier fanfiction', Falcon could be an interesting character to pair with the Winter Soldier. Falcon has his own set of skills and a strong moral compass. He could help the Winter Soldier navigate the modern world and his newfound freedom. Also, Scarlet Witch would be a fascinating pairing. She could potentially help him deal with his traumatic memories through her powers. And Bucky could also be paired with Doctor Strange. Strange could use his magic to help Bucky understand and control the dark forces within him.
The Winter Soldier is none other than Bucky Barnes. His transformation into this role was a result of manipulation and experimentation. Despite his past actions, he later strives for redemption and works to atone for his deeds.