Who is The Sentry? MCU’s Thunderbolts character origin & powers explained

With Thunderbolts finally starting production, here’s everything you need to know about Marvel Comics‘ most mysterious character, The Sentry. 

The upcoming Thunderbolts movie promises to introduce one of Marvel’s most unique superhero teams, and that includes the terrifying character The Sentry. 

The Sentry has all the obvious hallmarks of what appears to be a Superman knockoff. However, the character’s bizarre backstory and incredible powerset mean he’s much more of a force of nature than DC’s Man of Steel is. 

Who is Marvel Comics’ The Sentry?

The Sentry originally debuted in 2000’s The Sentry, a five-issue mini-series exploring his origins, before appearing in the modern Marvel Universe in New Avengers #1. 

In the story, Robert Reynolds learns that he once drank a serum, which gave him the power of a thousand exploding suns, and he became the superhero The Sentry. He’s so powerful and smart that he was best friends with Reed Richards and The Hulk, but he hides his powers and identity after learning of his dark alter ego, The Void. To prevent The Void’s return, Reynolds voluntarily erases his existence at the end of the story. 

Matt Murdock later discovers Robert imprisoned on The Raft, having voluntarily surrendered, believing he killed his wife, Lindy. Robert resumes his Sentry identity once more when he learns Lindy is alive. He learns that The Sentry comic is an in-universe publication that serves as a record of his exploits after everyone’s memories of him were erased.  

For a while, it was believed that The Void was a figment resulting from a “psychic virus,” but that turns out to be a lie. The Void is very real and constantly manipulates Robert, a reflection of a darker past that toys with his already fragile mental state. 

During the Siege event, it’s revealed that Sentry’s true origin is much darker: Robert is actually a drug addict who had drank the serum in search of his next high, killing multiple people when he gained his powers. Traumatized, he’s spent his life blaming his past on The Void, but the two are one and the same. 

Norman Osborn orders Bullseye to kill Lindy, which leads to the Void taking control and destroying Asgard. Void kills Loki in the ensuing fight, with Robert becoming lucid enough in the aftermath to ask Thor to kill him. 

The Sentry would be revived a handful of times over the years, but the original Robert Reynolds incarnation appears to be dead for good, with his soul being guided to Valhalla by Valkyrie. 

Most recently, Sentry’s powers manifested and chose several new hosts, who were murdered in quick succession by Ryan Topper, who wanted the power for himself. Ryan is eventually bested by another inheritor of the power, Mallory Gibbs, who chooses to continue in Sentry’s stead under a new codename, Solarus. 

The Sentry’s powers and weaknesses explained

The Sentry is potentially the strongest being who has ever existed in the Marvel Universe, save for cosmic deity figures like Eternity or The One Above All. 

It’s a little hard to explain how Sentry’s powers work, but the thrust of it is he’s detached from reality as a side effect of the Golden Sentry Formula. There is potentially no upper limit to his powers, with many regarding Sentry himself as being akin to a god. 

In most cases, the only reason Sentry is not classified as a world-ending threat are his own failings. While Robert is incredibly intelligent, he’s not entirely aware of the extent of his own powers.