Loki's season 2 finale opens with the God of Mischief utilising his newfound time-slipping abilities to travel back to the moment the Time Loom went into meltdown. He does so not only to save all those branches, but time itself.
Victor Timely dies a lot, and it takes centuries before Loki can successfully pull off OB's plan. Unfortunately, it still doesn't work. The Time Loom can't handle an infinite number of timelines, forcing the Asgardian to return to the Citadel at the End of Time moments before Sylvie killed He Who Remains.
Repeated attempts to stop her from murdering the villain fail and, finally, the Kang Variant intervenes. He knows about Loki's time-slipping because he paved that road as well. Yes, everything we've seen in season 2 played out exactly as He Who Remains intended; he never planned on dying at Sylvie's hands and, thanks to Loki returning to this point, the villain is reincarnated just as he predicted.
Despite Kang's attempts to get Loki to kill Sylvie so he can take his place (or perhaps join him) in the Citadel, the hero realises there's another way and, following an emotional reunion with Mobius and Sylvie, he chooses to destroy the Time Loom and dons a new costume, in the process.
The Multiverse wasn't created when He Who Remains died. Instead, its creation is happening now, and Loki is the one using his newfound abilities to keep it alive (the Loom's destruction initially killed the branches) and give his friends the chance to fight, and hopefully win, the war that's coming. It's bittersweet but as Mobius says earlier in the episode, "Most purpose is more burden than glory."
After the Multiverse takes on the appearance of the World Tree, we return to the TVA.
A new Miss Minutes is brought back online and we learn they're keeping an eye out for He Who Remains' Variants (none of them know the organisation exists). Mobius even mentions that one of them was "handled" in a 616-adjacent realm, referencing Kang the Conqueror's defeat in Ant-Man and The Wasp: Quantumania. With that, he decides to leave the TVA and visit the timeline he originally hailed from.
OB creates a new TVA Handbook, the young Victor is never given the earlier edition as a child, and Ravonna Renslayer wakes up in the Void where she's seemingly devoured by Alioth. She may well learn to control it, of course, though her fate is ambiguous.
Back to Mobius, and he watches his Variant as Sylvie approaches and suggests she plans on exploring the Multiverse. Then, we see an emotional Loki looking over that and every other timeline, seemingly the source of what's keeping them alive. To allow his friends to live, Loki takes He Who Remains' place as a benevolent God watching over a Multiverse, not one single "sacred" timeline.
Is this his final fate or will the God return to put an end to Kang once and for all? For now, that's down to the TVA, though we find it hard to believe this will be the last we see of the villain-turned-hero...