Crimson Dynamo

Boris Vadim, otherwise known as the Crimson Dynamo, is the main antagonist of the 2021 superhero film Mysterio: Path To Redemption and the posthumous overarching antagonist of it's 2023 sequel Mysterio Forever. He will return as the posthumous overarching antagonist in the upcoming third film.

He is a former member of the Winter Guard who killed his commanding officer for threating to court-martial him shortly after the Soviet Union's collapse, leading to his arrest, cryogenic freezing, and eventual transfer to La Santé Prison. He is the former cellmate and archenemy of Quentin Beck/Mysterio.

He was portrayed by Alden Ehrenreich in his first villainous role.

Tenure as a member of the Winter Guard
At some point in his life, Boris Vadim joined the Winter Guard, and was presumed to have gotten along well with his commanding officer. Shortly after the fall of the Soviet Union, Boris still wanted to carry out the Soviet's ideologies, but his commanding officer continued to persuade him to accept the change or be court-martialed. This prompted Boris to act on impulse and murder the commanding officer.

This, however, resulted in Boris being promptly arrested and cryogenically frozen for the next 33 years.

Incarceration at the La Santé Prison
After Boris Vadim was unfrozen, he was brought to La Santé Prison, where he met Quentin Beck/Mysterio, who was his cellmate. After Beck gets an early release, Boris is reminded that he has 9 years of his prison sentence left, much to his frustration, and begins planning an escape.

Escape from the La Santé Prison
During lunch time, Boris throws a tray at one of the prisoners, starting a prison riot, and giving Boris enough time to escape the prison. Shortly after this he plans on tricking the citizens of Manhattan, New York into thinking Mysterio is still a villain. It is implied that he forced the New York Times to print out the headline "Mysterio lies his way out of jail time".

Hiring Christopher Colchiss and Lancaster Sneed
Boris used a payphone to call Christopher Colchiss and Lancaster Sneed, and they agree to his plan after explaining it to them. It is implied that the trio robbed the bank and managed to pin the blame on Mysterio, resulting in him being falsely arrested and taken to the Metropolitan Correctional Center.

Boris's speech
Boris is about to make his speech about Mysterio still being a villain, but Quentin Beck interrupts his speech at Bowling Green Park by placing the disk that featured the explanation of his plan to. While his true intentions are revealed over a loudspeaker, the crowd starts to boo at Boris and begin pelting him with food, promptimg him, Lancaster, and Christopher to leave the area in humiliation.

Birth of the Dynamo
After arriving at Boris's lair, he threw a fit over his latest plan failing until Christopher and Lancaster arrive and inform him that they made a crimson red suit. When Boris sees the suit, he feels happy about it, then puts on the suit. After blasting his two assistants with his electric blast, he flies off looking for Mysterio.

Final battle and death
Boris, now calling himself the Crimson Dynamo, travels to Manhattan and threatens to bomb the entire city if Mysterio doesn't show up in 3 hours. After arriving, Mysterio offers Dynamo a truce, but he declines, starting his and Mysterio's big fight. After Mysterio is injured while his suit had suffered from some damage, Dynamo's suit is only scratched as they land on the Empire State Building. While Dynamo gloats about his plan, Mysterio uses green smoke to restrain him, and uses green lightning to critically damage Dynamo's suit, causing him to be flung into the abandoned Renwick Smallpox Hospital, causing the suit to explode upon impact, killing him.

Mysterio Forever
Boris doesn't appear in the film, but is seen on a child's drawing of the battle with Mysterio.

Trivia

 * Crimson Dynamo was included by Christopher Nolan because he felt that Black Cat would not be the right choice for the film.
 * Alden Ehrenreich revealed in the bonus feature on the Blu-Ray release of the film called Making Dynamo that he wanted Crimson Dynamo to be included in Mysterio Forever and the upcoming third film, and even though he didn't get to reprise his role in the finished film as well as not getting to play the Crimson Dynamo in the upcoming third film, he wished everyone involved the best.
 * In three of the four deleted scenes featured on the Blu-Ray release, the battle between Mysterio and Crimson Dynamo ended in a way that was different from the final film.
 * Boris loses his balance and grabs the edge of the roof, begging for Beck to help him, but he lets Boris fall onto the streets of Manhattan.
 * Boris fails to trick Quentin Beck into thinking that Boris was redeemed.
 * Beck disables the Crimson Dynamo suit and delivers Boris to the police.