Black Panther’s Abilities
The mantle of the Black Panther (the suit) gives him enchanted maneuverability and strength since it is woven out of Vibranium.
Super Soldier Serum
Dr. Erskine successfully used the Super-Soldier Serum on Steve Rogers who became the hero dubbed Captain America. The last remnants of the serum now only exist in Steve’s blood.
Winter Soldier’s Weakness
In Infinity War, Bucky Barnes turned to dust due to the decimation caused by Thanos. By Civil War, he was mostly free of the mind control and had been doing his own thing for a while.
Yelena Belova
Originally, Yelena was a foe of Natasha Romanova and was sent to kill her, but the two later became allies. She was also a member of S.H.I.E.L.D., Vanguard, and HYDRA; the latter organization changed her into a version of Super-Adaptoid. Yelena ended the movie "Black Widow" on a mission to free the other brainwashed Widows. In a post-credit scene, she was seen working for a mysterious figure called Contessa Valentina Allegra de Fontaine (aka Val).
Dark Avengers
The Dark Avengers appear in Marvel: Avengers Alliance and Marvel Puzzle Quest. This iteration of the group consists of Ares, Bullseye, Daken, Moonstone, Ragnarok, Sentry, Mac Gargan / Venom, and Yelena Belova.