It's clear at this point that the Marvel Cinematic Universe (MCU) is building up to Secret Wars. With the introduction of many characters like Kang the Conqueror, the Skrulls, the multiverse and more, you can easily put two-and-two together and theorize that Secret Wars is the next big event.
Now, with the said buildup, of course comes the question of who the next big bad will be. With Thanos completely rocking out the Infinity Saga, we definitely need an idea of who will be seen as the next big bad of the MCU.
So, who is the next logical answer then? Well, it has to be The Beyonder considering how big of a part he plays in the comics.
The Beyonder and why he might be the next big bad villain of MCU's Phase 5 in Secret Wars
Saying The Beyonder was a big part of Secret Wars would be putting it quite lightly. The villain was literally introduced in that comic. Created by James Shooter and Mike Zeck, The Beyonder first appeared in Marvel Super Heroes Secret Wars #1 in January, 1984.
One of Marvel's biggest villains, The Beyonder, is a part of an alien race called the Beyonders. According to Fandom, The Beyonder was dragged to Earth by the super-villain group Interl, to attract a vibranium meteorite.
Being fascinated by Earth over the years, The Beyonder realized that people on the planet weren't creations themselves, but rather made up the whole of a larger universe, which then made up the collection of many other universes, the Multiverse. For him, that was quite interesting as the Beyonder himself was complete. He was his own reality.
Not being satisfied by the fact that everyone on Earth was just contributing to a larger universe and not their own thing, he made it his mission to remedy this incompleteness.
In Secret Wars, he would then travel to Earth and possess those with superhuman powers which included the likes of Hulk, Spider-Man, Avengers and more. Soon, many of the heroes and villains of the Marvel universe would find themselves transported to a different planet called Battleworld, where they would duke it out against one-another.
With the multiversal aspect already being introduced in the Marvel Universe now, and with the introduction of Kang the Conqueror, we can surely expect Phase 5 to lead towards the big event from the comics.
With the rumored introduction of Doctor Doom as well, the reboot version of the storyline in the comics sees him play a major part in the storyline. So, if the Marvel Cinematic Universe does follow that storyline, we can at least expect a mix between the two.
All that remains is the introduction of the Beyonder, and to see how he might take a part in this storyline. Hopefully, we will soon get to see what plans Marvel has for the future of the MCU.