WARNING: The following contains spoilers for Loki Episode 6, "For All Time. Always.," streaming now on Disney+.
In the Season 1 finale of Loki, the God of Mischief and his more capable counterpart, Sylvie, reach the Citadel beyond the End of Time to confront the proverbial man behind the curtain. When they enter the stronghold, He Who Remains, a 31st-century scientist and the Sacred Timeline's all-knowing creator, informs them that the Time Variance Authority is a necessary evil guarding the multiverse against legions of destructive variants of himself. Without He Who Remains to monitor and protect the Sacred Timeline from uncontrollably branching, an all-out war of both infinite and unimaginable proportions would consume each new world.
Ignoring his warning, Sylvie kills He Who Remains, and his death spawns innumerable multiversal offshoots. Even though some fans have speculated Loki's arrival to a reoriented TVA headquarters where his friends don't recognize him is due to their memories being erased, this theory seems far-fetched given what's already known about the upcoming Marvel Cinematic Universe Phase 4 films. Furthermore, a keen-eyed discovery made by New Rockstars on YouTube gives a more plausible explanation for this reality-breaking event with franchise-altering consequences.
New Rockstars points out that the low-level, paper-pushing TVA agent Casey, played by Eugene Cordero, is renamed to "Hunter K-5E" in the Season 1 finale credits. Although his appearance is difficult to find, as his face is not visible on screen, it's safe to assume that Casey is one of the masked hunters running around the TVA headquarters at the episode's end. Interestingly, Mobius and B-15 seem to retain their previous job titles, which seemingly presents the possibility that this warped iteration of the TVA could be a rewritten version of the one visited throughout Loki's first season.
However, New Rockstars notes that the MCU established in Avengers: Endgame that Back to the Future logic doesn't apply to the films, as illustrated in Scott Lang's famous line, "So Back to the Future's a bunch of bullshit?" Therefore, Sylvie's decision to eliminate He Who Remains altered reality into a myriad of fragmented multiverses and by no means a rewritten one. This suggests that Sylvie pushing Loki through the time door and back to the TVA headquarters sends him to a separate timeline where Casey is assigned to a different department, not one where his friend's memories are erased, or their reality has been modified in any way.
This subtle end-credits clue regarding Casey ascribed as "Hunter K-5E" supports the fact that multiple variants of the same person will appear in the MCU's Phase 4 films sooner rather than later. The events of Loki open up the world of Marvel to an endless number of possibilities, such as recasts of characters and crossovers from multiple films, making the rumors of Tobey Maguire and Andrew Garfield entering the MCU in Spider-Man: No Way Home all the more credible. Additionally, since Sylvie's deadly handiwork created new deviations in the timeline, this means there is hope for Wanda to find variants of her sons in Doctor Strange in the Multiverse of Madness, considering that she heard them calling out to her in the final moments of WandaVision.
Indeed, Loki's Season 1 finale sets up the entire future run of the MCU in a dramatic fashion. Since fans know that these reality-altering changes will be in place during the upcoming Phase 4 films, the idea that anyone at the end of the first season had their minds erased doesn't seem probable. Instead, the odds are that the versions of Mobius and B-15 appearing in Episode 6 are variants from another existing timeline branch. Nevertheless, fans will have to wait to find out what theories are true when Loki Season 2 returns to Disney+.
Created by Michael Waldron and directed by Kate Herron, Season 1 of Loki is streaming on Disney+.