We have recently heard that Marvel has begun considering plans to introduce The Sentry in the near future of the Marvel Cinematic Universe. It is currently unknown how Marvel Studios plans to introduce the character. Many general audience members are likely not familiar with the character of The Sentry, however, he has a very rich history in Marvel Comics lore which you can learn more about below.
Sentry’s introduction into the Marvel universe was a unique one. He first appeared in Sentry #1, in 2000, and would later be reintroduced in New Avengers, as a member of that team. The interesting thing about him was that he was revealed to have been active in the comic universe since the 1940s, until a device built by Mr Fantastic and Doctor Strange wiped everyone’s minds of it, including that of the Sentry himself, due to them figuring out it was the only way to stop a villain named The Void (who turned out to be a personality of The Sentry). What’s the issue with this? Simple, it’s simply too heavy of a shift for the MCU to take. With the comic universe, it’s existed for 80 years now, so a character being active for about 10 of those? It’s not much of an issue. However, if we were suddenly told that Sentry had been there during the Battle of New York, one of only four of the Avengers battles we got to see (Maybe 5, if you count Civil War), and everyone just… forgot, it’d be essentially taking a sledgehammer to the existing continuity. This isn’t to say that retcons aren’t possible, they just aren’t possible on the scale that this route would require, considering that Sentry was essentially a Superman-level hero, especially when it came to publicity. So, that being said, what are some other routes that could be taken here?
1. The Void
The Void is the name used for the dark personality of the Sentry (or Bob Reynolds, his civilian name). Bob occasionally loses control, allowing the Void to take over, but the Void also finds ways of messing with him when he isn’t in control, which includes hallucinations. That leads me to the direction that could be taken: the Void leads the Sentry to believe that he’d been a hero in the past, when in reality he wasn’t, or, what could be cooler, he was actually a villain. This has been explored before in the comics, Sentry’s origin is shown to be a fun, 60’s-Lee story about a kid finding a serum at first, but in reality, it was a drug-addicted teenager breaking into a lab to try to find something he could use to get high, accidentally getting powers in the process. The contrasting of extremely light to extremely dark storytelling is a very unique way to tell his origin, and having him believe he’d been a hero, only to be shown he was the villain the entire time, maybe even using this to develop him into an actual hero, would be very interesting.
2. The Multiverse
Ever since the Spider-Man: Far From Home trailer name-dropped the multiverse, as well as Avengers: Endgame making reference to it, there’s been a lot of speculation about what would come of the concept. Would it be Miles Morales? The Fantastic Four? Well, what if it’s the Sentry? The thing about the Sentry’s story is that there’s a big leap to face when it comes to it, mainly, the idea that the heroes have the capability to erase a person entirely from history, and to do it easily. So, instead, what if only Sentry’s mind gets erased, and he ends up in a different universe, one where he was never active as a hero before? This means that once he gets his memories back, he’d remember entirely different dynamics with different heroes. Maybe on his world, Spider-Man’s an adult, the Avengers line-up was entirely different, things like that. It’d allow for the multiverse to be utilized in a cool way, and even show us glimpses of different worlds.
3. The Carol Danvers Play 
I mentioned earlier that I’m not entirely opposed to the idea of retcons, and to be clear: I’m not. In fact, there was a movie that did it quite well, also set in the MCU. Per Captain Marvel, a high-powered superhero has existed since the 90’s, but due to her not dealing with Earth-based issues, she hasn’t been referenced until now. There’s a bit of questionable continuity when it comes to that, but it still makes sense, and allows for a cool character to smoothly enter continuity. Sentry is the man of ‘A million exploding suns’, it would make sense that his adventures wouldn’t be limited to just Earth. As such, he could be a cosmic hero, that eventually comes home and loses his memory, just like in all of the other versions. This option isn’t ideal, as he would be a bit too similar to Captain Marvel, and it takes away the interesting dynamic that he has with Earth’s superhero community (or thinks he has, at least).
4. Similar… But Different
Even despite the now 22 entries in the franchise, the MCU still has many secrets in its history. Other than Captain Marvel and Captain America, everything before 2008 is still essentially a mystery, so, would it be possible for a hero to have operated in this time, staying fairly below the radar while doing so? Perhaps even making acquaintance with one or two heroes during that time? Definitely, and it would provide a middle ground of sorts, allowing for him to have still been in contact with the heroes, while not being an incredibly well-known superhero that would require the entire world being mind-wiped in order for him to be forgotten.
