Crossbones

"There are no prisoners with HYDRA, only order. And order only comes from pain. Are you ready for yours?"

- Brock Rumlow to Sam Wilson

Brock Rumlow is a HYDRA sleeper agent inside S.H.I.E.L.D. and the S.T.R.I.K.E. team leader. He's a world-class hand-to-hand fighter with an extensive experience in street-fighting and various martial arts and military combat techniques.

Biography
"S.T.R.I.K.E., you heard the Cap! Gear up!"

- Brock Rumlow

Brock Rumlow was an agent of S.H.I.E.L.D. who was often partnered with Captain America and the Black Widow.

One operation saw Rumlow assisting in the recovery of the stolen Zodiac weapon and the apprehension of the terrorists that stole it.

Agent Rumlow led S.T.R.I.K.E., Captain America, and Black Widow on a mission to recapture the Lemurian Star, a S.H.I.E.L.D. ship hijacked by Batroc the Leaper and his pirates.

After Hydra was revealed, Agent Rumlow fought his way into the control center, and threatened to kill the man in control of the Helicarrier launch sequence. A gunfight between S.H.I.E.L.D. and Hydra agents ensued, but Rumlow was able to get them in the air.

After his battle with Falcon, he managed to survive being burned and crushed under Helicarrier rubble when it crashed into the Triskelion.

Personality and Traits
Rumlow was shown to be incredibly loyal to HYDRA, as well as being slightly cocky, as when he saved Captain America aboard the Lemurian Star. He had a strong attitude, as well as a tendency to go to extreme lengths to do things, as when he threatened the Helicarrier controller.

Powers and Abilities
Peak physical condition: Displayed in his fight with Falcon.

Expert sharpshooter: Was able to hit a mercenary whilst parachuting onto the Lemurian Star.

Trained soldier: Shown when he successfully took the Lemurian Star.

Relationships

 * Captain America - Ally turned Enemy
 * Black Widow - Ally turned Enemy
 * Jack Rollins - Subordinate and Ally
 * Baker - Enemy
 * Falcon - Enemy
 * Nick Fury - Ally turned Enemy

Trivia

 * In Marvel Comics, Brock Rumlow is an agent of the Red Skull known as Crossbones.