The Marvel Cinematic Universe post-Avengers: Endgame has encountered serious changes in the world and galaxy that could have massive repercussions. While the Multiverse has become a major event, seeds were also sewn from before Thanos' attack. This included the presence of Skrulls, which was initially peaceful but has now grown more dangerous, as shown in the Secret Invasion trailer. But while the evil Skrulls don't speak for the larger race, it's proved that threats could come from anywhere at any time.
Spider-Man: Far From Home has already proven that while there were Kree sleepers cells on Earth, they were far from the planet's only threats. In fact, the Skrulls showed that time could change things, and while they were victims in the past, they still could do severe damage. Now that a group has proven this, with plans to overthrow world governments, it's also called back to a secret origin that may explain their aggressive behavior and even beckon the Eternals' return.
The Skrulls Share A Unique History With the Deviants
Like the humans of Earth, the Celestials visited the beings of Skrullos and conducted their experiments to create another trio of organisms. First, the traditional Skrulls had no abilities but could evolve like humans. Then, there were the Eternal Skrulls who, like humans, had powers meant to make a difference. Finally, the Deviant Skrulls were the only ones able to shape-shift and the most common in canon. The reason why they've become so common was that they started a war with the two other species, eradicating them and becoming the dominant species.
In the MCU, Deviants were a step towards the Eternals rather than a piece of the larger experiment that the Celestials conducted. But because they were so vicious, the Eternals were brought in to eradicate them. However, in the case of the Skrulls, should their Deviant roots be maintained, it's possible they evolved as Kro had, eradicated their Eternals and further grew and changed into what was introduced in Captain Marvel.
Secret Invasion Could Set Up A Return Of the Eternals
Secret Invasion is through and through Nick Fury's story. His life had always been about protecting people from unseen threats, and the Skrulls completely fit that bill. However, the activities that could threaten the planet's stability could, in turn, be enough of a beacon to call upon the Eternals that haven't been taken by Arishem. For example, on their quest to save their friends, Druig, Thena, Makkari and Starfox could learn of the Skrulls' roots and return to Earth, trying to stop the current threat to their home.
Should the Skrulls embrace their Deviant roots, it would mean that coupled with the Kree sleeper cells and Eternals, a significant conflict could arise. With Kree as the natural enemies to the Skrulls and the Eternals designed to stop Deviants, it could lead to an all-out war on Earth. While there are still good Skrulls in the galaxy, it's clear that the natural deviancy within them has continued to survive. But Secret Invasion could result in a turn for the better or something much worse.
Secret Invasion will start streaming on Disney+, on June 21st, 2023