Captain Britain/Brain Braddock

Brian Braddock is a English Student who stumbles upon an artifact, The Amulet of Might, which when infused with his body when his time of need activates it grants him superhuman abilities such as enhanced strength, durability, reflexes, agility, senses and speed. He is also immune to all known diseases and poisons. His greatest ability is actually the energy shield and blade he can conjure in his hands whenever he pleases. He became known as Captain Britain.

He was born in London and was a fairly popular student at a local school for troubled youths. While on a field trip one day he bought an amulet and planned on presenting it to his mother who was ill. Unfortunately, that day by the time he was home she was beginning to pass away and so he left home. Later he was attacked by Proxima Midnight who was determined to retrieve the amulet for Thanos, her husband. The Amulet fused with Braddock and gave him the power to overpower her. Later Nick Fury found him and trained him to control his power. He used this training to defeat Midnight and banish her from earth. He was later asked to join the Avengers, who at the time were Iron-man, War Machine and The Vision, who were still recovering from the events of Captain America: Civil War.

During this time he and the remaining Avengers attempted to trace down the mandarin but to no avail. He continued to train himself continuously so that if Proxima returned, he could defeat her.

In 2018, an ally of Midnight, Ebony Maw, attacked New York attempting to secure the power stone. Captain Britain was in the middle of tracing down the leader of a major British terror group and thus could not come to aid Tony Stark and Stephen Strange, who was captured. Braddock however, enlisted Nick Fury and the remnants of S.H.I.E.L.D. to join him, in the battle of Wakanda. By the time he arrived on the helicarrier, Midnight was about to kill Steve Rogers but was stopped when Braddock stabbed her through the heart killing her. Along with Rogers and Alpha, he was the last Avenger standing when Thanos attempted to take Vision's Mind Stone, he also managed to block an attack from Thanos with his shield thanks to it being a creation of the reality stone. However, he was swept aside after striking Thanos's chest with his sword and it doing nothing. He also was the only Avenger along with Black Widow to survive the explosion of the Mind Stone. However, his allies were resurrected when Thanos used the Time Stone to reverse the explosion. He survived the Snap and was the only person, apart from War Machine and Rocket Raccoon, not part of the original Avengers team to do so.

During the Infinity Crusade to reverse the Snap, he along with Captain America and Captain Marvel dueled Thanos, he was also witness to the resurrection of Bucky Barnes due to Alpha swapping Steve Rogers soul for Barnes' as Rogers body died. He also slew the resurrected Proxima Midnight during the battle of the Sanctuary at the climax of the Infinity Crusade. He also witnessed Pepper Potts sacrifice her life to undo the snap much to the dismay of Tony Stark. He remained part of The Avengers after the Infinity Crusade.

Poverty in London
"All my life i grew up without hope of being able to do something to help anyone, i always had to look out for myself where i was from but now, now things are different, i'm gonna be superhero! They can call me... Brian Man!" - Brian to Nick Fury when being told he had gained the powers of might.

Brian grew up in a lower class family but when he was 5 years old his father was killed in an explosion, his mother who had been battle cancer at the time withdrew from society. Braddock was raised by his aunt who worked constantly to make sure Braddock still grew up like any other child, eventually while on his first school trip to a museum, something which he had saved up for, he bought his mother a gift to bring home. After arriving home he found out she had passed away that day.

Braddock left home without knowing where he was going and on his way back to the museum to try and sell the amulet back, he was attacked by Proxima Midnight, the amulet fused with him allowing him to gain the powers he needed to defeat her, after she had fled. Nick Fury showed up at his house, ready to explain that Braddock's life was about to get a whole lot bigger.

Brian-Man
Nick Fury took him away from his home to a S.H.I.E.L.D. - MI5 base, where he explained that Braddock had fused with an Amulet made from the Reality Stone, something the Avenger Thor had secured five years prior. He stated he would try and help Brian control his power and in return Braddock had to join The Avengers, as they needed a new super soldier. Braddock excitedly agreed stating he wanted to be a superhero and that he would call himself Brian Man.

Fury struggled for a long time to control Brian's cocky attitude and excitable nature and almost gave up on him, but upon meeting up with Steve Rogers he pushed through and finished training Braddock. Unknown to him Rogers and Braddock had spoken, with Rogers explaining the sacrifices of being a superhero to Braddock which caused him to change his attitude. This also convinced to Brian to rename himself in honor of Steve Rogers, he re brands him to Captain Britain and pledges to defend his home country.

Showdown with Proxima Midnight and Supergiant
As soon as Fury was sure that Braddock was ready to begin testing to see if he was worth adding to the Avengers team, Midnight returned having kidnapped Brian's aunt. Braddock faced Midnight and fought her Outriders and her sister Supergiant. He mortally wounded Supergiant when he deflected her attack with his shield and she retreated. When only Midnight was left she executed Braddock's aunt and fled also. Braddock swore he was kill her before destroying her teleport which allowed her to move freely between Sanctuary and Earth.

Joining the Avengers and tracing the Mandarin
In late 2017 Alpha returned to Earth to assist the Avengers in tracing the Mandarin, since the Mandarin had the highest human kill count Alpha wanted to see him put down in order to restore peace on Earth. During this time Captain Britain and Alpha became good friends. Eventually they were unable to trace the Mandarin and the two fell out over Alpha refusing to break the Eternals code of tapping into the Infinity power to take out the Mandarin. Since it was not a Universal threat Alpha could not use his full power, Alpha left Brian to continue tracing the Mandarin while he responded to an Attack on New York by helping track down Scarlett Witch and Vision alongside Captain America, Black Widow and Falcon.

The Battle of Wakanda: Backup Arrives and The Demise of Proxima Midnight
While the battle of Wakanda began, Brian was still tracing the Mandarin so it wasn't until Alpha mentally reached out to him to call him to Wakanda that he gave up and joined the fight. Along the way, Brian reached out to Nick Fury and Maria Hill who gathered the remnants of S.H.I.E.L.D. to fight. Upon Arriving in Wakanda, Brian led the soldiers into the battle by dropping in from the Helicarrier. He was just in time to save Steve Rogers from being choked to death by Proxima Midnight, as he ended the assassin's life by piercing her heart with his sword. He then presented Captain America with his Shield after Proxima destroyed his Wakandan one.

The Avengers vs Thanos
After Alpha wiped out the outriders, Thanos arrived on Earth and Alpha began to destroy the Mind Stone, having Omega and Sigma hold Wanda Maximoff back, meanwhile The Avengers, including Captain Britain, held Thanos back. They were all easily swept aside apart from Captain America and Captain Britain who held Thanos back long enough for Alpha to destroy the Mind Stone, however, in the process Thanos killed Steve Rogers by punching his head so hard his Brain shut down. All of the Avengers apart from Black Widow and Brian were wiped out in the explosion which followed the destruction of the stone, however, Thanos reversed all the deaths, including Steve, when he restored the Stone. After that Alpha and Thor attempted a final attack on Thanos however, he snapped his fingers beginning the end for half of the Universe, before fleeing. Captain Britain was one of the few Avengers to survive the Snap.

Recovery
After the Snap the Avengers returned to the facility in New York, but quickly the military arrived to arrest Steve Rogers, Natasha Rominoff and Sam Wilson. However, Alpha declares the Universe in a state of emergency and declares himself the one that makes all decisions now, when Ross attempts to arrest him, Alpha puts him into a trance which sends him away to remove all crimes from Steve, Natasha and Sam's records. Thus removing their criminal status. News reporters arrive and Brian as well as Natasha tell the story of Thanos and that their is nothing they can do to help. Inside the Avengers discuss their losses, Bruce announces that they have to assume Tony died in the snap along with Peter Parker and Stephen Strange, meanwhile Rocket attempts to contact the Guardian's with no avail. Outside Ant-man arrives with someone.

Paging Captain Marvel
The woman introduces herself as Carol Danvers and she states that Nick Fury summoned her, and that she has been preparing for this in the Quantum Realm for years. When Pepper Potts arrives stating she has to save Tony, Alpha, Brian and Rocket agree to go with her to save Tony who she received a distress signal from. Alpha who is now very weak states he cannot teleport them and that they will have to travel to space themselves. Meanwhile, Carol explains her plan to assemble their own Infinity Gauntlet to use against Thanos.

Personality
"'You're an Idiot'""'An idiot with a cool new name and bangin' set of new superpowers, Oh My God, this is going to be so amazing, i wonder if they will end uip making a movie about me!?'""'No one likes Superhero movies in the first place never mind a movie about you'"- Nick Fury and Brian Braddock

Brian is at first someone who cares for those close to him but he can be very over excitable sometimes as well as quite cocky. However, once he becomes Captain Britain he matures. He is quite a sarcastic and witty individual who can still be quite excitable.

Upon joining the Avengers he takes his job very seriously and dedicates himself to tracking the Mandarin only stopping upon being summoned to Wakanda to defend the Universe against Thanos.

Powers

 * Enhanced Strength: Due to the Amulet of Might's fusion to Brian's DNA he has above average strength matching that of Captain America, potentially, Brian maybe stronger since his power came straight from the reality stone. Brian has been able to even fight beings such as Thanos while he wielded 5 infinity stones.