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[MCU] How would the events of the MCU play out, if Hela had never been cast out and imprisoned?

In this scenario, Hela -- while still a blood knight who loves war -- decides to go along with Odin's new stance on benevolence. Thor is born, with an older half-sister as part of the family, and Loki is still adopted. Unlike in the main universe, Loki has a big sister, with whom he develops a close sibling bond, to the point where people assume Thor is simply a tag-along. 

How would these changes affect the MCU?
gpt
**Plot of Thor movies**

I think Loki would probably actually bond with Thor more than Hela.  The two of them really do get along when you take out Loki's childhood jealousy of him, which he has because Thor seemed like the favorite and was first in line for the throne.  Loki would be super jealous of Hela, and try to scheme to replace her.  

But Thor also never becomes the hero/Avenger we know today because Loki's scheme with the frost giants is what gets him cast out to Midgard in the first place, which is where he matures and finds his worthiness.  Then defeating Loki had him cast out where he met Thanos and kicked off the events of the first Avengers.  Malekith would be killed much easier, and the Asgardians would keep the Reality Stone in their vault. 

**Basic MCU plot**

So the Avengers don't form when they did (probably going on to form mini-teams), though Cap, Iron Man, and the Hulk are out there.  Iron Man's solo movies play out pretty much exactly the same, without his PTSD in the third but him and Rhodey become heroes together.  

Winter Soldier happens since Cap would have been working for SHIELD, where he finds he can trust the Falcon and Black Widow.  Cap would still go after the Buckster to try to bring him back.  Widow, Falcon, and possibly Hawkeye via Widow would be there to support him. Coulson takes over SHIELD in Fury's fake-death.

Ultron is never built and since Loki never brought the scepter to Earth, Scarlet Witch, Quicksilver, and Vision are never created.  Sokovia is also not destroyed so Zemo is chill.  

Ant-Man's series plays out exactly the same - so he still meets Falcon. 

Black Panther plays out slightly differently.  Because Civil War never happened, T'Chaka is still king when Killmonger shows up.  Killmonger kills T'Chaka, so T'Challa fights him and then the movie plays out pretty much the same way from there.

Doctor Strange happens in exactly the same way.

Spider-Man still gets his powers, Iron Man doesn't take him in so he fights Vulture without the suit and still wins.  

**Infinity War**

By the time Infinity War takes place, the heroes are much more  fragmented.  Doctor Strange has the Time Stone - Thor, Hela, and Loki have the Reality Stone - SHIELD has the Space Stone - the Power Stone is on Xandar - the Soul Stone is on Vormir - and Thanos still has the Mind Stone. 

Thanos needs the Space Stone early so he can get around as easily.  Things actually don't work out for him despite the lack of powerful Avengers.  He probably still fucks up Xandar for the Power Stone so he has the strength to actually fight people.  Then his next target would be Earth.  Because he never used Loki to probe its defenses he thinks little of the planet and has no idea of any Avengers.    
He attacks the SHIELD facility where the Space Stone was kept, where Coulson calls in his best people.  Cap, Hawkeye, Widow, and Falcon get the call and get fucked up by Thanos who takes the Tesseract.  Falcon calls Ant-Man for backup in the aftermath, who just got back from his adventure with the Wasp.  

Meanwhile Cull Obsidian and Ebony Maw show up in NYC for the Time Stone.  They're met by Iron Man, War Machine, Doctor Strange, and Wong.  Wong cuts off Obsidian's hand again, little Spider-Man shows up and impresses Mr. Stark who makes a mental note to take this kid in.  Maw brings Strange to his ship, Iron Man follows but has to duck out when Spidey falls off due to lack of oxygen.  War Machine bursts into the ship to save Strange, he's unfortunately not a match for Ebony Maw - but he distracts him enough for Strange to free himself and escape back to Earth as War Machine is killed.        

When Doctor Strange gets back, he finds Tony in the Sanctum with Spidey and Wong and Agent Phil Coulson of SHIELD who is putting together a team to combat these aliens.  

**The Avengers form** 

The Avengers are Iron Man, Doctor Strange, Wong, Captain America, Black Widow, Hawkeye, Falcon, Spider-Man, and Ant-Man and the Wasp.  They have to defend the Time Stone against a Thanos with the Power Stone, Space Stone, and Mind Stone.  When Thanos attacks the Sanctum with his forces, he's met with heavy resistance.  The Sanctum's defenses are such that an actual penetration by hostile forces is exceedingly difficult, because it's helmed by two master sorcerers with all of their relics on hand.  The sorcerers and Iron Man+Cap's team hold off or kill most of the Black Order when a beam of light crashes down.  Midgard is under the protection of Asgard and an attack by a non-Asgardian hostile force is worth its best.  So the bifrost beams down Thor, Hela, and Loki who kill all the Outriders.  A three stoned Thanos is either beaten to death by a less heroic Thor or stabbed to death by a more heroic Hela.  Either way he dies.