Crossbones

•Expert Tactician: Due to his military training, Rumlow is a highly skilled strategist with extensive knowledge of warfare. After leaving HYDRA, Rumlow was able to stay ahead of the Avengers and the police for six months, successfully leading a terrorist group to achieve his goals.
•Master Combatant: Rumlow is a formidable hand-to-hand combatant. He has faced terrorists, pirates, and SHIELD agents on his missions, even managing to subdue, disarm, kill, or severely injure his opponents. He was able to stand his ground against Romanoff and almost against Rogers using his new equipment, but lost because Rogers had superior enhanced reflexes.
•Knife Mastery: Rumlow is highly skilled in using a knife in combat. This is quickly seen when he drew his knife and disarmed Sharon Carter before she could react. Later, he killed several S.H.I.E.L.D. agents with a combination of knives and weapons. As Crossbones, he used the retractable blades of his gauntlets during his fight with Steven Rogers, and the latter managed to dodge his quick stabs and cuts due to his enhanced reflexes.
•Master marksman: Rumlow is a skilled marksman, able to shoot a rope with a crossbow to catch Rogers and prevent him from falling off a building, or accurately hit a target's head with a single shot while skydiving.
• Spy: Rumlow managed to conceal his true identity as a HYDRA sleeper agent within SHIELD, forming a partnership with Rogers and Romanoff in the process.
•Assassin: Rumlow is highly skilled at killing his targets, as seen when he coordinated a simultaneous shooting spree against several pirates to rescue hostages. He even ambushed other SHIELD agents, eliminating them in quick succession during the Battle at Triskelion.

•Enhanced Strength: Utilizing the hydraulic functions of his specialized gauntlets, Rumlow gained superhuman strength. This augmented his physical attributes enough to rival even Steven Rogers.
Pain immunity: Suffering severe burns, Rumlow's pain receptors were altered, making him almost completely immune to pain. When Romanoff tried to electrocute him with his gauntlets, Rumlow informed him that he felt no pain as he had before, but he still screamed in pain once he self-destructed by activating the bomb in his vest.

Rumlow soon located Steven Rogers and threw a bomb at his shield, causing Rogers to throw it away from people, only to then be unexpectedly attacked by Rumlow. The two fought, and Rumlow commented that he wanted revenge for what Rogers had done to him during the Battle of Triskelion. When Rumlow had him against the wall, he decided to activate a blade from his gauntlet to pierce him, but Rogers dodged his attacks and ripped off his gauntlets. Still refusing to surrender, Rumlow continued fighting; however, Rogers delivered a series of blows, damaging his mask, and with a kick, defeated Rumlow. Rogers made him remove his mask and interrogated him to find out who his buyer was, but Rumlow refused to answer and told him that James Barnes had remembered him when he was still operating as the Winter Soldier, distracting Rogers. Suddenly, Rumlow activated his suicide vest, causing an explosion that would have killed Rogers and several civilians around him; however, Wanda Maximoff used her powers to contain the explosion. She then guided Rumlow away from people until he lost control near a building, killing dozens of civilians. Surprised, Rogers asked Wilson to call an ambulance. The attack on Lagos, and Rumlow's catastrophic suicide bombing that killed dozens of civilians, created a public relations disaster and, with divided opinions about the Avengers after the Battle of Sokovia, paved the way for the Sokovia Accords in the hope of preventing a similar conflict.

Seeking to draw out the Avengers, Rumlow gathered a group of mercenaries and orchestrated the theft of a bioweapon from a lab at the Infectious Disease Institute. Rumlow's men drove a truck through the entrance, before opening fire on the guards, filling the building with poisonous gas. Rumlow made his way through the building, using his battle suit to easily penetrate several walls until he found the bioweapon and stole it. However, they were soon confronted by the Avengers, who intervened and subdued the mercenaries. As Rumlow exited, he saw Wanda Maximoff sucking in the poisonous gas, and quickly organized his escape, while Steven Rogers searched for him in the building. Rumlow soon found Natalia Romanoff fighting his men and attacked her, grabbing her by the hair and dragging her back. Romanoff broke free and confronted him, before attempting to electrocute him in the neck with a disc, but Rumlow informed her that he could no longer feel pain. He then locked her inside the truck where they were standing and dropped a grenade with her, although Romanoff managed to survive.
Rumlow and his remaining mercenaries climbed into their armored truck, and Rumlow took control of the main weapon, aiming it at the building just as Steven Rogers came out to pursue him. While Rogers was escaping, Rumlow fired at him until he was finally able to knock him out of the building, sending him falling several stories to the ground. They stopped the truck at a market, where Rumlow gave the bioweapon to one of his men to take to the airport, and they split up. However, all his men were defeated and the bioweapon was recovered by Natalia Romanoff.

However, on his way, Rumlow was ambushed by Samuel Wilson, whom he confronted and pushed to the ground. As Rumlow prepared for the fight, he told Wilson that in HYDRA there were no prisoners, only order, and that order was obtained through pain. Wilson simply told him to shut up, and they continued fighting. As Rumlow gained the upper hand, he threw his opponent across the room, but while taunting Wilson, he didn't notice a Helicarrier collapsing near the building until it was too late. Rumlow tried to escape, but was soon caught and crushed by the collapsing building. He managed to survive despite burns and debris, gaining horrific facial and body scars, and was transported by medics to a hospital. Months later, while still recovering from his injuries, Rumlow watched a report on the fall of S.H.I.E.L.D. from his hospital bed, and was surprised to learn that Alexander Pierce had also died during the conflict. Disillusioned and furious at HYDRA's defeat, he proceeded to attack his nurse and escaped. [4] Seeking a new purpose, Rumlow decided to become a mercenary and began raiding police stations in several countries, before hiring a group of thugs. By recovering some items from S.H.I.E.L.D.'s research labs and setting up an arms sale, Rumlow attracted some HYDRA agents, with whom he opened fire to send them the message that he no longer worked for them and to get his revenge, subjecting them all to the same pain he had suffered. As his actions gained media attention, Rumlow adopted the alias "Crossbones" and vowed revenge on Steven Rogers. Having become a target of the Avengers, Rumlow moved to Lagos, Nigeria, to orchestrate a deadly ambush.

When they exited the vans to proceed with their assignment, Rumlow ordered his men to dig three graves for the corpses; however, he was shocked to discover that Rogers and his team had escaped by punching a hole in the van where they were being transported, as Maria Hill had infiltrated the guards escorting them to aid their escape. Moments later, Rumlow and Rollins escorted Alexander Pierce to a HYDRA base to begin interrogating James Barnes, who was struggling to understand why he seemed to remember Rogers from somewhere. Rumlow acted as Pierce's bodyguard when he began interrogating Barnes, but the latter remained unresponsive. As a result, Pierce ordered his memory wiped again so he could assassinate Rogers. Rumlow made his way to the Triskelion control center to ensure the launch of the Insight Project Helicarriers while Steven Rogers revealed HYDRA's infiltration of SHIELD — When Cameron Klein refused to launch the Helicarriers, Rumlow threatened to shoot him in the head. Sharon Carter came to Klein's defense, pointing her gun at Rumlow's head. A shootout between SHIELD and HYDRA agents began, but Rumlow was able to get the Helicarriers airborne and escaped. On his way through the Triskelion, Rumlow managed to kill several SHIELD agents, using his knife and disarming them to shoot them with their own weapons. He received a call informing him that Natalia Romanoff and Nicholas Fury had apprehended Alexander Pierce. Knowing that Pierce's capture would jeopardize Project Insight, Rumlow made it his priority to reach Pierce.

In their respective vehicles, Rumlow arrived at the shopping mall with the STRIKE team, but despite a desperate search, they couldn't find the two fugitives, as they were disguised as ordinary civilians to go unnoticed. The unit thought they had already left, while Rumlow was communicating with Jack Rollins, and suddenly he looked away when he saw a couple kissing, who were actually Rogers and Romanoff successfully hiding from them. Later, Steven Rogers and Natalia Romanoff were located at Camp Lehigh, where the hard drives of Arnim Zola's computer were located, learning about HYDRA's plans. Knowing this, Alexander Pierce ordered the camp to be destroyed with a missile; Rumlow explored the area shortly afterwards, looking through the rubble and discovered a pair of footprints, deducing that Rogers and Romanoff had survived and escaped. After reporting this to the base, Rumlow asked them to call James Barnes. Eventually, Rumlow and his STRIKE team captured Steven Rogers, Natalia Romanoff, and Samuel Wilson on the streets of Washington, D.C., after they had a prolonged fight with James Barnes. While Rumlow and his team surrounded them, ordering the three to kneel, he noticed that Jack Rollins was ready to execute Rogers by shooting him in the back of the head, but Rumlow saw that a news helicopter was watching them, and ordered him to wait until they were away from the media. Immediately afterwards, Rumlow decided to move the prisoners to a safe place for their execution.

The meeting between Steven Rogers and Alexander Pierce resulted in Rogers being declared an enemy of S.H.I.E.L.D. because he possessed key information about the death of Nicholas Fury that could compromise HYDRA's secrets. When Rumlow and the STRIKE team were sent to capture Rogers in an elevator along with other undercover HYDRA agents, Rumlow spoke to Rogers to gain his trust, mentioning his regret over Fury's death. However, Rogers soon suspected that all the agents accompanying him planned to arrest him on Pierce's orders and gave the team a chance to escape; they refused and attempted to subdue Rogers using magnetic cuffs. After a brief fight, Rumlow and Rogers were the last men standing, with Rumlow insisting that what he was doing wasn't personal. Although he was able to momentarily gain the upper hand, Rumlow was quickly defeated when Rogers knocked him out by throwing him against the elevator ceiling and commented that it felt very personal, before escaping the building after encountering a unit waiting for him outside the elevator. Despite his defeat at Triskelion, Rumlow led the subsequent pursuit of Rogers under the orders of Alexander Pierce and Jasper Sitwell, as sooner or later Rogers would discover that HYDRA was infiltrated in S.H.I.E.L.D. and would thwart their attempts to activate Project Insight. HYDRA was able to track Rogers to a mall in Washington, D.C., when he and Natalia Romanoff activated the USB drive containing a tracker.

Shortly after, Rumlow and the STRIKE team joined Rogers moments after the latter subdued several enemies on the ship, with Rumlow shooting a pirate who was aiming at Rogers. After receiving thanks from Rogers for covering him, Rumlow, Rollins, and the rest of the STRIKE unit made their way through the ship, and once Rogers and Romanoff were in position, they killed Georges Batroc's subordinates and rescued the hostages, including Agent Jasper Sitwell. While Rumlow and STRIKE escaped the ship with the recovered hostages, he informed Rogers that Romanoff didn't meet them. Rogers personally fought Batroc, who ultimately escaped SHIELD custody after Rogers was momentarily distracted by finding Romanoff hacking the ship's system to steal classified information on the direct orders of Nicholas Fury, jeopardizing the mission. Later, Rumlow accompanied Steven Rogers to the hospital and witnessed the operation on Nicholas Fury, who had been attacked by a masked man, which was secretly a HYDRA-orchestrated assassination attempt. Natalia Romanoff arrived and questioned Rogers about the shooter when Maria Hill joined them and told them that the ballistics were impossible to identify. Then, they watched as the doctors tried to revive Fury, but he didn't react, seemingly dying. Rumlow remained with his STRIKE unit at the hospital awaiting further orders after Nicholas Fury was pronounced dead, overseeing the situation. When he received a call from Triskelion, Rumlow informed Steven Rogers that he needed him to return to Triskelion to be interrogated by Alexander Pierce about what happened. Rogers initially delayed because he was talking to Romanoff about the identity of the anonymous assailant who attacked Fury, but Rumlow insisted that he had to go immediately.

Brock Rumlow was a S.H.I.E.L.D. agent who eventually led the S.T.R.I.K.E. team. As S.T.R.I.K.E.'s leader, he often partnered with Steve Rogers and Natasha Romanoff. During his career, he became a double agent working undercover for HYDRA, a terrorist organization aiming to create a new world order. In 2012, after the Battle of New York, Rumlow was present at Stark Tower after Loki was apprehended by the Avengers. Natasha Romanoff gave him and his men, including Jack Rollins, the Scepter to return to S.H.I.E.L.D. However, they were secretly ordered by Alexander Pierce to deliver the Scepter to List for HYDRA's purposes. In one operation, Rumlow assisted in the recovery of the Zodiac weapon stolen by a terrorist group. Rumlow, along with Steve Rogers and Natasha Romanoff, apprehended the terrorists led by Baker. Baker then attempted to escape by jumping from a window, so Rogers also jumped and fought Baker in mid-air. Finally, Baker returned the Zodiac to Rogers and deployed his parachute, while Rumlow fired his grappling hook from a crossbow to pull Rogers back to the top floor. Rumlow led S.T.R.I.K.E., accompanied by Steve Rogers and Natasha Romanoff, on a mission to recover the Lemurian Star, a S.H.I.E.L.D. vessel that had been hijacked by Georges Batroc and his pirates. After Rumlow briefed the team on the plan and the hostages they had to rescue, Rogers left the Quinjet first, while Jack Rollins asked him if he was using a parachute, but Rumlow denied it.