When Drax debuted in Guardians of the Galaxy, one of his driving motivations was to kill Thanos, who the warrior claimed had killed his family. The specifics of the situation weren't detailed, though the commentary track on Avengers: Infinity War confirmed how the Mad Titan's genocidal methods were repeated on multiple planets.
At one point in the film, we see a flashback to how Gamora became Thanos' surrogate daughter. The tyrant went to Gamora's planet, arbitrarily separated the population in half and executed one half in hopes of "balancing" the universe's resources. Co-director Joe Russo noted that this is how Drax's family had been killed.
"Here's a call back to Drax's History with Thanos," Russo explained on the commentary. "His planet was treated the same way as Gamora's planet. Drax was put on one side, his family was put on the other."
When Drax and Gamora met in Guardians of the Galaxy, one of their commonalities was that they both were driven to kill Thanos for personal reasons. As revealed by Russo's comments, their motivations for the murder were more similar than they had realized.
Sadly, neither Drax nor Gamora were able to accomplish their objectives, with Thanos killing Gamora in order to obtain the Soul Stone while Drax was killed by Thanos' deadly snap that killed half of the universe. The deaths of this many heroes took a huge emotional toll on audiences, though that was the directors' goal all along.
"It was always a plan to show beyond that because when we made the decision to have the snaps themselves, that's a plot trick to cut to black after an incident like that happens," Joe Russo previously told ComicBook.com. "And it doesn't give you any emotional resonance or catharsis. What he said thinking about it realistically; the true heartbreak doesn't lie in the fact that he snapped his fingers, it lies in the fact that people have to watch loved ones, and we have to watch characters that we care about die. And that's where the real heartbreak lies for the characters who live in the Universe and for those of us watching the movie."
With Guardians of the Galaxy Vol. 3 slated to hit theaters in 2020, both characters will likely return somehow, though we'll have to wait until Avengers 4 on May 3, 2019 to discover how that happens.
How do you feel about this connection between Drax and Gamora? Let us know in the comments below!