News broke earlier this year that Kingsley Ben-Adir had landed a lead role in Secret Invasion as a villain who will clash with Nick Fury and Talos. Rumour has it that Marvel Studios was eyeing the likes of Gary Oldman and Denzel Washington for the role, so this character is no doubt a major addition to the MCU.
Murphy's Multiverse has shared a few intriguing new details, including the fact that, as suspected, Ben-Adir will play a Skrull. However, they've also learned that his shape-shifter has a storied history with Talos and speculate that he could be playing Paibok or Kl’rt. The latter is, of course, the Super-Skrull, which suggests he could be introduced here prior to when he gains the Fantastic Four's powers.
As for Killian Scott's mystery character, he's said to be playing one of Ben-Adir's cronies. That no doubt means he's a Skrull as well, and the site points out that Klrr is a likely possibility for him.
That character infiltrated Stark Industries and was the star of the Meet the Skrulls series we've heard could be the inspiration for Secret Invasion. It's been clear for a while now that we're not getting an action-packed adaptation of the original comic book event series, with Marvel Studios instead leaning more into the "Who Can You Trust?" aspects of the story than the Avengers fighting Skrulls.
It would be a waste not to adapt the Kree/Skrull War at some point and throw Earth's Mightiest Heroes into the mix, but who knows what Secret Invasion could be setting the stage for.
The series is expected to arrive on Disney+ in late 2022.