However, Red Skull saw his true intentions, informing Gamora that Thanos was, in fact, weeping for Gamora, as he truly loved her as a daughter, and was heartbroken that he had to sacrifice her to get the Soul Stone. Disbelieving, Gamora could not comprehend that Thanos ever showed genuine love for her.
Since Gamora was most regularly successful in advancing his ideals and vision for the universe going forward, he favored her, equating her successes with love.
Probably, the user may probably see the one he loves the most, or the one who was sacrificed for the Soul Stone. Gamora fulfills both the criteria. She was the one Thanos loved the most, also she was sacrificed for the Soul stone. Probably this is the reason Thanos saw her moments after the snap.
Gamora, Quill, Drax and Mantis traveled to Knowhere to attempt to stop Thanos from getting the Reality Stone from the Collector. During their journey, Gamora made Quill promise to kill her should Thanos get ahold of her, saying she had information which he could use to destroy the entire universe.
He was obsessed with manipulating Gamora to continue her life as his dependent. The Mad Titan might've given Gamora a few moments of softness, but it isn't worth the mental abuse. Nebula received the more obvious form of abuse, which was physical abuse.
Avengers Infinity War 2018 Thanos Kills Gamora Death Scene HD Bluray
Did Thanos feel guilty for killing Gamora?
However, Red Skull saw his true intentions, informing Gamora that Thanos was, in fact, weeping for Gamora, as he truly loved her as a daughter, and was heartbroken that he had to sacrifice her to get the Soul Stone. Disbelieving, Gamora could not comprehend that Thanos ever showed genuine love for her.
When Gamora finally does confront Thanos, she believes for a moment that she's killed him and breaks down, crying. An orange light passes over her--but it's fleeting. Whatever love Gamora has for Thanos is all but smothered by darkness.
Thanos eventually realizes that all the trouble he went for in the snap: Killing Gamora, Killing Asgard's population, and ruining lives, have been for nothing. Thanos commits to finding a solution to reverse the snap. He starts to repair the gauntlet and confronts the Avengers.
Over the years, Gamora became Thanos' favorite child, and he considered her the future heir to his throne, which only strengthened the growing wedge in her relationship with Nebula and in time, Gamora built up the reputation as the "deadliest woman in the galaxy" and became well known throughout the cosmos.
On Earth, the Snap led to a five-year period in which the world fell into societal collapse and many countries abandoned their national borders. In 2023, the victims of the Snap were resurrected by the Avengers, after they went back in time to alternate timelines to acquire their own set of Infinity Stones.
In 2018, Thanos had captured Nebula and accessed her memory drive, discovering that Gamora knew the location of the Soul Stone. Forcing her to divulge the Soul Stone's location by torturing Nebula, the pair traveled to Vormir.
Tony made the decision consciously to spare her. The only things he knows of Gamora are that she is Nebula's sister, and that she was killed the first time Thanos retrieved the Stones.
Thanos never cared much for Nebula, even going so far as to say in Guardians of the Galaxy that Gamora was his favorite. That could be because, to Thanos, Nebula was nothing more than a means to spare Gamora while still obtaining the Soul Stone.
He repeatedly talks about the variant Gamora as if she is the same girl who fell in love with him, but she just does not remember those events. It is possible that Star-Lord thinks that the 2014 Gamora is the MCU's main Gamora and that she was brought back to life by Hulk's snap only without her memories.
While audiences never got to see Quicksilver at full power, super-speed is one of the best abilities a hero can have when facing an enemy like Thanos. With enough training, Quicksilver would have been more than capable of defeating Thanos when he finally arrived in Infinity War.
Another prevalent argument is that the God of Thunder was simply too exhausted at that point, having used all of his energy fighting Hela in Thor: Ragnarok.
As Cates has pointed out on Twitter, it's important to point out that “Thanos” is still Thanos' real name, and that “Dione” was what his mother originally wanted to call him before he was born. What do you think of the name originally intended for Thanos?
When she, Mantis, and Drax are trapped, Mantis calls out Nebula's outbursts of frustration for what they are– Nebula's coping mechanism for shielding real emotion. It's only when Nebula hears Rocket's voice after he wakes up that she starts to cry. Nebula has never cried over anyone, not even Gamora.
This was part of a cosmic process by which the wielder of the Soul Stone had to sacrifice something they truly loved. Thanos killed Gamora regretfully, showing he would truly do anything to accomplish his goals, no matter how much it hurt him personally.
