Warning: This post contains spoilers for Thunderbolts.

Thunderbolts introduces audiences to one of the lesser-known villains in the Marvel Cinematic Universe, a seemingly ordinary guy named Bob, portrayed by Lewis Pullman. While he may appear unassuming, wandering around in his pajamas and barefoot, Bob is at the center of a darker narrative that involves experimentation led by Valentina Allegra de Fontaine, played by the talented Julia Louis-Dreyfus. As the head of a CIA operation, Val's ambition is to create and manipulate a superhuman, striving to develop her own iteration of the supersoldier serumthe same serum that transformed a frail Steve Rogers into the formidable Captain America.

In a pivotal scene, a member of Val's team cautions her about the unpredictable nature of injecting someone inherently good, like Steve Rogers, with the mysterious serum, juxtaposed with the unpredictable consequences that can arise if the subject has a troubled psyche. Bob, who becomes both Sentry and his sinister counterpart, The Void, is not the sole subject of Val's experiments; however, he is the only one to survive the harrowing process. When Val discards what she believes to be Bob's lifeless body into a bunker, intending to erase all evidence of her unethical activities, fate has other plans.

As Val faces a congressional investigation, she resorts to burning the bunker along with her personal assassins, including well-known characters played by Florence Pugh, Wyatt Russell, and Hannah John-Kamen. To their shock, they discover that Bob is not only alive but has developed extraordinary abilities. He possesses immunity to bullets, the power of flight, and an unsettling capability to delve into the darkest memories of others simply by touch.

Throughout the film, we learn that Bob grapples with significant mental health struggles, stemming from a traumatic past that includes an abusive father, a battle with meth addiction, and a tendency to indulge in dark fantasies. He confides in Yelena, revealing his cyclical experiences of euphoric highs and devastating lows, often resulting in blackouts where he awakens to the aftermath of his destructive actions. The serum exacerbates Bob's mental health conditions, giving rise to his two distinct personalities. Val, in her hubris, plans to present Sentry as her crowning achievement, meticulously crafting his superhero persona with a flashy costume, styled hair, and a fitting name.

Initially, Sentry revels in his newfound identity, basking in the belief that he surpasses even the Avengers in terms of power. He exhibits grandiose delusions, even likening himself to a god. Yet, Val's control over Sentry begins to wane, prompting her team to activate a kill switch in a desperate attempt to neutralize him. This attempt backfires spectacularly, unleashing The Voida being that can seemingly annihilate individuals with a mere flick of his hand, transforming them into shadows. In reality, The Void traps his victims within a twisted reality constructed from their worst memories, alongside scenes from his traumatic past.

In a daring rescue, Yelena manages to navigate The Void's dark labyrinth, ultimately aiding Bob in escaping his darker self and saving New York City in the process. Following these events, Sentry is welcomed into the newly formed super-team, informally dubbed the Thunderbolts after Yelena's childhood soccer team. The group is later rebranded as the New Avengers, with Sentry expected to join forces with notable allies including Yelena, her father Red Guardian (played by David Harbour), Avengers veteran Bucky Barnes (Sebastian Stan), Captain America wannabe John Walker (Wyatt Russell), and Ant-Man's adversary Ghost (Hannah John-Kamen) in upcoming films.

Bob's dual identity as Sentry and The Void finds its roots in the comics, where Robert Reynolds is portrayed as a character plagued by schizophrenia and anxiety. In a desperate search for a high, he steals an experimental serum from his science professor, unaware that it is, in fact, a supersoldier serum. This sets off a cascade of events, leading him to alternate between being a hero as Sentry and a villain as The Void, a character capable of disintegrating his victims in a cloud of shadows.

In a thrilling post-credits scene for Thunderbolts, the newly established super-team laments their composition, which they feel is lacking in true power. Bob, casually enjoying a burger and milkshake in a lounge chair, expresses regret over his inability to utilize his impressive abilities effectively. He remains unaware of how to control his powers and fears that if he engages in battle against invading threatsbe it aliens or HYDRA agentsthe Void may emerge.

However, a sense of urgency looms large as Yelena unveils satellite imagery showing an inter-dimensional ship entering Earth's atmosphere, adorned with the iconic Fantastic Four symbol. This revelation hints at a tumultuous path ahead, as the impending arrival from the parallel universe could foreshadow dire consequences for the New Avengers.