Remember when a computerized Armin Zola caused major damage to the MCU by telling Steve Rogers and Natasha Romanov that HYDRA got a lot of agents into SHIELD in Winter Soldier? Many thought it was the end of the world.
That’s nothing compared to the season finale of Loki. He and Sylvie (Sophia DiMartino) meet the man behind the TVA, and are given an impossible choice. This leads to a decision that causes severe damage to reality, much less the MCU.

SPOILERS BELOW

Much of the episode takes place at the Citadel at the End of Time, which looks like a deserted wing of Hogwarts. Loki and Sylvie meet Miss Minutes, who offers them the chance of getting everything they ever wanted. Naturally, they don’t buy it. Strangely, MM also gives Renslayer the TVA files she deserves, not wants. More on that later.

Loki and Sylvie eventually meet the Man Behind the Curtain, He Who Remains. Fans recognize him as Jonathan Majors from Lovecraft Country and suspect who he could really be. Let’s say he’s expected in a future Marvel movie or two.

Much of the episode is a little boring, as fans didn’t expect a long discussion between three supposed bad guys. Still, HWR maintains an advantage throughout. He can travel way too fast for Sylvie to kill him and admits he literally scripted the whole thing, from Loki being grabbed by the TVA (and maybe what happened in The Avengers) to Sylvie causing her destruction. For a minute, some would be forgiven if he was Ultimate Loki.

He’s really a Variant of a scientist from the 31st century who discovered multi-verses, and encountered other versions of himself. It worked out for a while, until evil versions of himself (maybe someone named Kang) started conquering multi-verses. It caused a war, and he wound up making the TVA.
He gives Loki and Sylvie an offer: kill him and cause another multiverse war, or take over the TVA. The job’s taking a toll on him, and maybe he can turn it over to them.
Or maybe he expects them to choose chaos to get what they want. It’s really hard to read HWR, and Majors does a great job. He doesn’t look like a guy who’s a scientist, a warrior or conqueror. He looks ordinary, but has the knowledge to be anything but that.

Loki considers his offer, but Sylvie’s need for revenge (starting from when the TVA arresting her as a girl) is very strong. This leads to a couple of battles between the two, as Loki doesn’t want her to make things worse. Their problem is she can’t trust anyone and he can’t be trusted.

What about Renslayer (Gugu Mbatha Raw) and Mobius (Owen Wilson)? He’s arguing why removing free will from reality is worth it. To her, necessary lies are important to explain the status quo, including the Timekeepers and such. It’s not clear if she knows why the TVA was created, though.

What happens to her is actually disappointing. She just leaves for some “free will” and leaves Mobius behind. The only hint of where she could be..is somewhere she isn’t. Hunter B-15 (Wunmi Mosaku) heads to a high school in Ohio, and finds someone who looks like Renslayer but isn’t her. It may have been her pre-TVA version, as everyone is a Variant. That explains the pencils similar to the one that was shown in episode two.
Her role should not be over. Maybe she’ll be in the upcoming Spider-Man movie or Multitude of Madness.

Now, the moment that reboots the MCU several times over..
Loki tries to stop Sylvie by saying he doesn’t want a throne, especially HWR’s, but he wants her to be OK. This leads to what a lot of us were waiting for.

Sylvie then gives her answer to Loki:  “I’m not you”, She shoves him back to the TVA, and kills HWR.
He smiles, and says he’ll be seeing her again. She just sits, at the end of time, as the timeline is set free.

This doesn’t make her just like Peter “Thanos’ Snap is his fault” Quill. Who’s to say if Renslayer’s decision to arrest Sylie as a girl may have led to all this…and HWR knew it?

For a while, Loki tries to process everything. He started as being the cause to the timeline being shattered. It ends with Sylvie being the true culprit and he’ll be blamed for it because, well, he’s Loki. Eventually, he sees that he has to do something. He finds Mobius and D-15, but they don’t recognize him.
Loki then sees this, realizing he’s in a much different TVA. Yes, there’s only one Timekeeper, but many versions of him are running around causing trouble.
Isn’t this where Loki came in?

So what now? This will change Phase 4 in many ways, not likely at Eternals or Shang-Chi (although that is not certain). Will Sylvie just stay at the Citadel or will a different version of HWR (maybe one called Kang) help her escape?  Where is Renslayer hiding, and will Mobius realize what’s happening? Could Kang (one of the evil versions of HWR) battle a teenager and a sorcerer soon? The only thing we know is this:

By then, Loki will wonder what will be harder: fixing the Sacred Timeline or convincing people he’s not the bad guy this time.
Until then, fans will meet someone who asks what would have happened if things were different.