In the MCU, The Void is a place beyond time and space where things that have been "pruned" or eliminated from reality go to be destroyed into nothingness by the monstrous Alioth. It's played a major role in the Loki streaming series as well as in the recent Wolverine and Deadpool, with several characters who were trapped in the void potentially escaping. But with the official debut of the new Thunderbolts* trailer, which seems to confirm the casting of Lewis Pullman as Bob Reynolds/The Sentry, new questions are being raised about what that could mean for The Void, because in comics, The Void is also the name of The Sentry's villainous dark side, who is powerful enough to challenge the entire Avengers and more.
What is The Void in comics? In comics books, The Void is a being of dark energy who is connected inextricably to The Sentry , a superhero who has "the power of a thousand exploding suns" with an equally powerful opposite, evil personality - that being The Void. The Sentry has a bizarre Marvel Comics history. In his origin, Robert Reynolds is a meth addict who breaks into a lab to find drugs, only to ingest an experimental compound called the Golden Sentry Serum.
Obtaining amazing cosmic power, Reynolds becomes addicted to the drug, but eventually turns himself around and becomes one of the strongest heroes in the Marvel Universe to adventure alongside the Avengers, the Hulk, the Fantastic Four, and even the X-Men. But through it all, The Sentry struggles against The Voi.