10 Essential Avengers Villains Not Yet Used In The Movies
6. Sin
While it seems like the mysterious disappearance of the Red Skull seems to have fallen to the wayside, there's still space to bring in a literal and spiritual successor in Sinthea Shmidt, aka Sin, the Red Skull's genetically enhanced daughter, who's gotten the reputation for being crueller, madder, and more dangerous than her father. Which is saying something, considering he was a literal Nazi.
Unlike the Red Skull, alongside a proficiency in weapons and hand to hand combat, she also possesses some level of psionic power, giving her a skillset that makes her an even bigger threat than her father in many ways, and a terrifying villain for Cap and the team to go up against.
Though known to be beautiful, a storyline which sees her face disfigured in a manner similar to the Red Skull gave her an iconic look that would serve to make her even more terrifying than her already vast powerset implies, and would work well in a cinematic setting.
Her appearance in the MCU as a whole would not only serve to present a maniacal villain to throw down with, but also a revitalisation of the Skull's legacy after The First Avenger.