Let’s track this from the beginning.
-----2014: Guardians of the Galaxy-----
The Nebula we see in GotG is far from the Nebula we know and love today, being a far less sympathetic evil *******. She kills and kills without remorse, even trying to murder Gamora on multiple occasions throughout the film. Since this movie was about building up the Guardians themselves, it makes sense as to why they spent less time on Nebula and just sorta shoved her into a minor antagonist role. Her relationship with Thanos isn’t explored further past “he likes Gamora more” and her relationship with Gamora isn’t explored past “rivalry because Thanos likes her better”. However, we still get the first couple glimpses into the deeper part of her character: the moment she finds out that Ronan is plotting to kill Thanos after decimating Xandar, she immediately goes along with his plan. Not because she doesn’t care about the people of Xandar (she doesn’t but that’s besides the point) but because she finally sees a way to break away from her abusive father and maybe kill him in the process. With how damn powerful and influential Thanos is, there’s no way Nebula could kill him on her own. She’ll side with anyone to get away from him, even someone as disgusting as Ronan. This is our first real hint into how troubled Nebula is because of this toxic relationship with this grape looking ************.
-----2017: Guardians of the Galaxy Vol. 2-----
This is where **** starts to get real. Nebula has a lot more screen time in GotG Vol. 2, so she gets a lot more development into her character. Or, more accurately, her character in relation to Gamora.
We first see her when she’s brought to the Guardians by the Sovereign as a prisoner after attempting to steal some of their
Harpulary Anulax batteries. Gamora says that she’s “worth nothing more than the bounty due to her on Xandar” and, uh, accepts their “gift”. This isn’t true though, as we can see couple minutes later; Gamora refuses to give Nebula a Yaro Root because it wasn’t ripe. While this is obviously a comedic scene, the fact that Gamora cares about Nebula enough to even take something like that into consideration is extremely telling of her deeper feelings for her. While they may hate each other, and they’re only sisters because of an abusive genocidal megalomaniac bringing them together, they’re sisters nonetheless.
After most of the Guardians head to Ego’s planet, Nebula, Rocket, and Groot have a brief excursion on the Ravager ship. Nebula does something pretty damn interesting here: she saves Rocket and Yondu’s lives. While she probably does simply want her cut of the bounty, she also probably cares for them on some level: the Guardians are important to her, considering how important they are to Gamora. Anyways, the talk she has with Kraglin is pretty damn important; as it’s the first time she truly vents about her issues with Thanos and Gamora. She was never able to defeat Gamora in training battles, and every time she would lose Thanos would replace a part of her with mechanical parts, hence why she’s basically a cyborg. This is why she harbors such resentment towards Gamora. Not because Thanos liked her better, Nebula doesn’t give two ****s about that. It’s because she directly suffers from Thanos liking her better, and from Gamora being better. Of course, this is unfounded hatred. Gamora was just doing what she had to do to survive, and on some level Nebula knows that. But pain’s a complicated thing.
After the final battle with Ego (where Nebula does the most badass **** in any of the Guardians movies when she powers a goddamn spaceship using her own body) she has an incredibly heartwarming talk with Gamora. Don’t really need to explain or analyze this, it speaks for itself.
- Gamora: Nebula… I was a child like you. I was concerned with staying alive until the next day, every day. And I never considered what Thanos was doing to you. I’m trying to make it right. There are little girls like you… across the universe who are in danger. You can stay with us and help them.
- Nebula: I will help them by killing Thanos.
- Gamora I don’t know if that’s possible. (hugs Nebula) You will always be my sister.
-----2018: Infinity War-----
Not much happens here in terms of Nebula action. She gets tortured and Gamora gets incredibly upset at the sight, and Nebula gets upset when she finds out that Gamora’s dead, both of which further emphasize their strengthening relationship. Besides that? Not much.
-----2018-2023: Endgame-----
I've already went over how good the paper football moment with her and Tony is, so I'll just quote that post.
She has a heartwarming moment with Rocket after the Benetar touches down, where she sits and holds hands with him. This shared moment between them is a sign of just how much Nebula has come to care about the Guardians over the years and also it’s not romantic don't believe
@Shishœ's lies Nebula Is Not A Furry
She becomes a member of the Avengers for the next five years, and the fact that she finally has the closest thing to a family after so long is pretty sweet. The friendship she forms with Rhodey over “not being whole” is incredibly heartwarming. But the main event here is the T I M E H E I S T
Let’s track this from the beginning.
-----2014: Guardians of the Galaxy-----
This version of 2014 Nebula (who I will henceforth refer to as 2014!Nebula) is actually quite different from the 2014 Nebula we know and love to hate. This is for two specific reasons, both tying into Thanos’ abuse and manipulation:
- Our Thanos says “Perhaps I treated you too harshly” before he gets debrained by Thor
- 2014!Thanos doesn’t kill her for our Nebula’s betrayal even though Maw is all in on doing so, and instead sends her on an incredibly important mission to him.
Now we all know at this point that despite doing nothing wrong, Thanos does not care about Nebula in the slightest. He’s simply doing this as a tactical move, not because he likes her in any way. He's straight up manipulating her into thinking she's more important to her then he actually is. This explains why she doesn't side with our Nebula and the Avengers at all throughout the third act.
-----Back to the future, 2023: Endgame-----
The confrontation between 2014!Nebula, 2014!Gamora, and our Nebula (and Jeremy Renner I guess) was very meaningful to Nebula's arc as a whole. Here's 2014!Nebula, who's mistreated, abused, traumatized, and broken. And here's our Nebula, who grew out of that awful situation, who gained a healthier mindset, who made friends and connected with a family. This was Nebula facing her demons. And if there was just more time, if the situation was different, if there wasn't any risk of total universal genocide, perhaps the outcome could've been different. But Nebula killing 2014!Nebula was poetic in a way. She finally put a rest to her self doubt, to her baggage. To her demons. And with the death of Thanos, her arc is finally complete. Really excited to see where she goes in GotG Vol. 4.
