Avengers: Infinity War redeemed through the assistance of some unexpected allies. Though Peter Quill had some undeniably heroic moments throughout the entirety of Phase 3, Infinity War saw what is without a doubt his most questionable act to date. While facing down Thanos with a group of other heroes, Quill learns that his significant other, Gamora, has been killed by the Mad Titan, sending him into a rage that sabotages the heroes' plans and sees the almost successful effort to take Thanos down fail.
This moment is one of the most criticized in all of Star-Lord's Marvel Cinematic Universe history, as many were frustrated at the fact that Peter could have gotten the revenge he wanted if he had just controlled his anger and continued to go along with the plan. In fact, a considerable amount of those who saw Infinity War ended up blaming Quill for the Snap and the lives lost in it, as he sabotaged a plan that looked like it was going to work as a result of his own emotions.
But Phase 4 of the MCU looks set to turn this around based on what has been revealed about Star-Lord so far. As Eternals - a group that was actually created by the Celestials in the comics in order to protect the Earth. With the MCU seemingly reluctant to introduce actual Celestials to the universe - as only Peter's father Ego has been shown in any detail - it is therefore more likely that Quill will end up being able to use his Celestial heritage to convince the alien Eternals Earth is worth fighting for upon seeing them, making up for his actions in Infinity War.
While the Eternals were created to defend the Earth, and thus may wish to do so without any convincing, much of the MCU lore currently suggests this may not be the case - such as the fact no Eternals showed up to help during the events of Infinity War or the Eternals are aware the Celestials made them in order to protect the Earth, they may be slightly disillusioned with the idea, given their creators appear to have totally abandoned them, hence the current absence of Celestials in the films. The only alternative to this would be for Ego to have created them in order to guard the seed he left on the planet in an attempt to try and conquer it, at which point they'd likely only become more jaded should they learn this truth.
With many of Marvel's film heroes having arcs that see them combat and come to with their own disillusionment about being a hero, the stage is set for the Eternals to need a little extra push to convince them Earth is still worth defending - and there are few better prepared for the role than Star-Lord, a man who is both human and Celestial, and who also had his own upsetting experience with a Celestial. Since Quill is no doubt still blaming himself for letting Thanos' plan succeed pack in Phase 3, having him connect with the Eternals and be integral in convincing them to save the world could also provide him with some positive character development, and help him make up for what he likely considers his past mistakes.
Eternals is currently one of the most ambitious MCU movies to date, as the group is arguably one of the most obscure Marvel groups to have ever been given such a mainstream spotlight. However, the Guardians of the Galaxy themselves weren't initially well known by fans not versed in the comics, and their films still proved massively popular, so it's very likely Eternals will have the same success. That said, the film would benefit from having some larger links to the current MCU, and thus it's only fair to hope Phase 4's Eternals does capitalize on this connection between Star-Lord and the Eternals, as it would ultimately benefit both parties.
