I'll mention a few things I found interesting. But initially we saw a Marvel retrospective, showing timelines, with Loki's voice in the background; it's very beautiful.
Soon after, there are several scenes of the X-Men fighting alternate versions of heroes, dealing with incursions; the X-Men have a bomb that destroys the rival planet; the X-Men win all the confrontations, including the one in the Spider-Man/Tobey Maguire universe; Deadpool and Wolverine; and other X-Men are shown defending their world. I remember seeing Iceman, Colossus, and Jean Grey, who are killed.
We see a sequence from the final scene of Avengers: Endgame, Tony's funeral, from a different perspective, with Steve Rogers going to the past and talking to Scott Lang about the consequences of time travel and remaining in the past; Scott was the only one who knew what Steve was going to do.
Soon after, the Fantastic Four universe appears, we see the family, we see Doctor Doom, and we discover that Steve and Peggy are there.
Next we see the 616 universe, we see Sam's life and his Avengers, a training session at Sam's house, then we see the Thunderbolts minutes before the post-credits scene of their movie, fighting thieves, Mel appears guiding the group in Avengers Tower.
The two groups are warned about a threat coming from space. Doom is on the ship with Steve Rogers and the Fantastic Four. They meet with the two Avengers groups to ask for help. There's a lot of discussion, and they head to Wakanda because they need a mastermind to deal with the incursions. Shuri asks Namor for help, and he joins the group.
Cut to Thor and his daughter, Love warns Thor that a threat is coming; she's been having nightmares about Doom and the incursions, about the end of everything, and that everyone will die. Thor gets worried and returns to Earth. They go to New Asgard, we see Valkyrie taking care of Amor, and Thor goes to Wakanda and finds everyone.
A lot happens that doesn't need to be mentioned.
They split into three groups: one goes to the Fantastic Four universe, another to the X-Men universe, and the other to the TVA. Steve wants to go there to talk to Loki because it was Loki who sent Steve to the Fantastic Four universe.
The heroes plus Doom who go to the X-Men universe have a confrontation with them.
When the spaceship arrives on the X-Men's Earth, Nightcrawler suddenly appears inside and attacks the heroes. There are some great fights; Cyclops destroys Sam Wilson, Yelena corners Mystique, Shang-Chi has scenes with Gambit, but soon everyone resolves things.
Monica Rambeau appears; she's "sick" from living in another universe. A lot happens, and there are many conversations.
There are several scenes in the TVA with Steve, Thor, and Loki; they have a beautiful reunion as brothers! The TVA is completely destroyed; a flashback shows Doom fighting Sylvie, and TVA agents Mobius and B15 appear, but they are also killed by Doom. Loki does not die.
After discovering that Doom is the villain, Steve and Thor return to the X-Men's Earth and confront Doom, who reveals himself as the true villain to everyone on the X-Men's Earth.
It has one of the most insane action sequences I've ever seen; we see several robots leaving a department and heading towards the X-Mansion, all controlled by Doom, and the heroes fight against Doom and the robots.
Gambit, Thor, Steve, Cyclops, and Namor against Doom, a 5 against 1, Doom kills Nightcrawler and Mystique, Yelena asks Bob to try to fight, Sentry goes after Doom, who after taking a beating loses control and the Void takes over.
The Void attacks the heroes; Xavier desperately tries to stop it by entering Bob's mind. Xavier is killed by the Void, but manages to control it. Other characters and extras die, but these are the most interesting ones for now.
After several events, Steve and Thor confront Doom, who reveals his plan, saying he needs Reed and Sue's son to create a new world.
Doom then captures Franklin from the ship that was being protected by Herbie. Herbie is controlled by Doom and ends up becoming his servant.
A portal opens and Doom enters, Steve goes with him, they go to Doom's universe (the same as the Fantastic Four's), they go to Latveria, we see his castle and his servants, all dressed as witches, Doom tells his story to Steve, and we discover that Doctor Strange is his ally, along with Clea.
Doom kills Steve's son.
The heroes in the X-Men universe devise a plan to go after Doom, using Xavier's brain to find Franklin and discovering he's in the Fantastic Four universe.
While they discuss the plan, another incursion occurs, the X-Men's Earth becomes the target, debris begins to fall across the country, suddenly Storm appears from the sky, but is unable to stop it, and Sentry ascends to the heavens and single-handedly prevents the incursion; it's insane.
Sue tells Reed that she is pregnant with another child.
Reed contacts Ben and tells him everything that happened; everyone prepares for war.
All the heroes are gathered at Reed and Sue's house, except for Thor, who returned to the TVA to protect Loki, knowing that Doom would return.
The heroes invade Latveria but are stopped by an army of Doombots and witches; there's a Hulk version in the army fighting against the Thing.
Doom is not yet in the battle; Reed realizes Franklin isn't there either.
They find Steve wounded inside the castle. Doom, Franklin, and Strange are in the Void, trying to reach Loki.
Loki sends Thor to the Void, who fights Doom and Strange. Suddenly, a group of exiled variants appears, sent by Loki; there's a Ghost Rider among them.
Thor encounters versions of himself and Loki, including an older Loki. Doom nearly kills Thor, rips off his arm, uses magic to enter his mind and shows him New Asgard being destroyed and Love being killed. Thor is weakened, but Loki appears and saves him, confronting Doom.
Doom captures Loki and returns to Latveria, preparing a ritual.
All timelines are out of control and incursions are happening wildly. Doom asks Strange to use Franklin to transform the timelines into a kind of orb where all universes are trapped.
The battle outside the castle intensifies, Doom fights Sam, Cyclops, and Reed simultaneously, while incursions occur and universes die, including the X-Men's universe which is heading towards Earth-616.
Namor causes an insane tsunami.
There are incredible scenes of Magneto versus Doom; Magneto dies.
Shuri has great fight scenes with the Wakandans.
Cut to Earth-616, we see the sky turning red and a planet approaching, several familiar characters witnessing the end, Wong appears creating a shield, Kate, Kamala, and Cassie are shown discussing whether to call themselves the Young Avengers.
Carol Danvers appears asking Kamala for help with the bracelets, saying she found Monica on the planet in the sky, but the scene cuts back to the battle in Latveria.
The scene cuts back to the battle in Latveria. Several heroes die, including Bucky, and when all seems lost, Thor appears with an Asgardian army and Void variants.
It's an insane mix of characters. A lot happens and I'm too lazy to talk about everything, but it's fight after fight until the final incursion. Scott Lang has the idea to enter the Quantum Realm to survive, and a group succeeds.
Everything is destroyed and we see Doom creating his own world where he is God.
The film is NOT complete; there are several unfinished and random scenes, such as Carol and the Young Avengers one.
We also didn't see a post-credits scene; apparently, it doesn't exist yet.