Crossbones

Frank Grillo will reappear as Brock Rumlow in Captain America: Civil War, with his new identity, Crossbones. And if the character’s role in the Civil War comic book arc is anything to go by, he could be very important in the movie’s climax.

Crossbones was responsible for the death of Captain America in that story and, if that turns out to be the case in the Marvel Cinematic Universe, he could be the man whose move brings the titular war to an end.

Imagine, if you will, that the fight between the two teams of superheroes is ongoing and, out of the blue, a bullet from Crossbones’ gun kills Captain America in front of his allies and former friends – the battle would come to a halt then and there, as they all realize what matters most.

And now, on to the most powerful character on this list.