Sentry has one of the most twisted and convoluted origin stories in Marvel Comics, and it’s a big part of what makes him such a compelling character. His backstory is a mess of trauma, addiction, and cosmic power, all wrapped up in a fractured psyche that’s as dangerous as it is tragic. Here’s the breakdown:
Sentry’s origin starts with Robert as a junkie, a lowlife meth addict desperate for a fix. He breaks into a lab where he stumbles upon a secret super-soldier serum—a leftover from the Weapon X program, juiced up with some experimental cosmic sauce. He drinks it, and boom, he’s suddenly got “the power of a million exploding suns.” That’s not hyperbole; it’s how his power level is described. Instantly, he’s one of the most powerful beings in the Marvel Universe, on par with or exceeding heavyweights like Thor or Hulk. But here’s the kicker: the serum didn’t just give him power—it split his mind and birthed the Void, a dark, apocalyptic alter ego that’s basically his ID unleashed. The Void isn’t just a villain; it’s a part of him, a reflection of his guilt, self-loathing, and repressed rage.
What makes this so fucked up is the psychological toll. Robert’s not a hero by nature—he’s a broken man who accidentally becomes a god. He tries to do good as Sentry, but his mental instability and the Void’s constant presence mean he’s a walking disaster. Early on, he’s retconned into Marvel history as this Golden Age-style hero who’s been around forever, but his mind’s so shattered he can’t even trust his own memories. Turns out, he begged the world—including his best friend Reed Richards and Doctor Strange—to erase him from existence because he couldn’t control the Void. They mind-wipe everyone, including him, to forget he ever existed. That’s some dark shit: a guy so powerful he’s a threat to reality, yet so fragile he’d rather be unmade than live with himself.
Then there’s the reveal that the Void killed his wife, Lindy, in a fit of rage—or maybe he did it as Sentry and blamed the Void. It’s ambiguous, and that’s the point. His whole deal is unreliable narration. He’s schizophrenic, delusional, and his perception of reality is a mess. Every heroic act he does is shadowed by the fear that he’ll snap and end the world. In Siege, he loses it completely, and the Avengers have to take him down—Thor yeets his corpse into the sun. Even then, he comes back, because death doesn’t stick for a guy like him.
Why does this matter for Thunderbolts? The upcoming MCU movie is bringing Sentry in, played by Lewis Pullman, and it’s heavily implied if not outright shown he’ll be the major antagonist. If they water down his origin—make him just another strong guy with a generic villain arc—they’ll miss what makes him tick. Sentry’s not a straightforward hero or villain; he’s a cautionary tale about power without stability. The Thunderbolts are a team of antiheroes and misfits, and Sentry fits that vibe perfectly—a wildcard who could save them or doom them. His addiction, his mental illness, the Void—it’s all crucial to showing why he’s not just a Superman knockoff but a deeply human fuck-up with godlike power. Strip that away, and you’re left with a bland cape guy. Keep it, and you’ve got a story that could rival the best MCU character arcs, like Tony Stark’s or Loki’s. Messing it up would be a disservice to one of Marvel’s most unhinged and tragic creations.
*just found out that Sentry's creator has been involved from the beginning with Sentry's character in Thunderbolts and is basically contracted to write a Sentry project!!!