9. Arnim Zola
Arnim Zola made a surprise return in Captain America: The Winter Soldier as his robotic alter-ego, revealing that he had been working undercover for Hydra during the formation of S.H.I.E.L.D.
Seeing the duplicitous former ally of the Red Skull get up to mischief in this series on their behalf would help to expand upon that particular plot point, making this series an essential viewing experience for those fans hoping to bridge the gap between the events of Captain America: The First Avenger and the recent sequel.
Regardless of whether it’s a brief cameo or even a detailed look at how he turned himself into a computer virus of sorts, there are definitely more than a few interesting storytelling possibilities here, while Toby Jones is tremendously fun in the role.