WARNING: This post contains major spoilers for Captain America: Civil War. It's best to read after you've seen the movie.

References to The Empire Strikes Back are nothing new when it comes to Marvel movies. 

Marvel chief Kevin Feige is such a fan of the second Star Wars movie (or Episode V) that he's squeezed references into a bunch of the Marvel Cinematic Universe movies. Ever notice how someone's hand gets cut off in every one of the Phase Two Marvel movies? That's a direct nod to Empire's climactic scene between Luke Skywalker and Darth Vader. In fact, Feige has referred to the entirety of Phase Two, which includes everything from Iron Man 3 through Avengers: Age of Ultron, as the "MCU's Empire Strikes Back."

Captain America: Civil War takes things even one step further by solidifying itself as the movie that most feels connected to Empire and will most influence its subsequent film, like Empire did for Jedi. Codirector Anthony Russo says they even referenced the Star Wars film in their pitch, calling Civil War a "down beat in the saga."

So what exactly gives Civil War an Empire-like vibe, to the point that -- like Empire is to the Star Wars franchise -- it's now being heralded as Marvel's best movie?

Well...

It literally references Empire Strikes Back

Okay, let's get this one out of the way first because it's the most obvious. During the airport sequence, Spider-Man presents a plan to take down Giant-Man (formerly known as Ant-Man) by referencing the moment in Empire when Luke uses a grapple line to tie an AT-AT's legs together.

It's a very amusing moment that reminds the audience it's okay to have fun even though all your favorite Marvel heroes are currently putting the smackdown on one another. The structure of the scene itself also mirrors that big Hoth moment in Empire in that, like the rebels, Team Captain America is just trying to get the hell out of there.

In Empire, it's Han, Leia, Chewie, and C-3PO all trying to blast their way to the Millennium Falcon. In Civil War, it's Captain America, Winter Soldier, Falcon, Scarlet Witch, Hawkeye and Ant-Man all trying to blast their way to the Quinjet. Also, both scenes represent the most sprawling and memorable action sequences in their respective films.

Its masterful balance of tone

Tone is a tricky thing in a film, and when you walk away not liking a movie, much of the time it's because the tone was off. Maybe it's a comedy that tried to throw in some dramatic beats and fell flat. Or it's a drama that tosses in an over-the-top comedic scene that feels like it's from a completely different movie.

Civil War is at times the funniest movie you've seen this year, and within minutes you're on the verge of tears. It's comical, but it's deep, and at times it hurts. That's not easy to do. Empire Strikes Back is another film that has this masterful control over its tone, consistently mixing its lighter, more comical moments with a deeply personal plot that's slowly inching towards the most gut-wrenching finale.

Black Panther is the new Lando!

He's calm, cool and collected. He looks good in a suit and is also a confident leader. Who am I describing?

Lando Calriss... no, wait -- Black Panther!

Chadwick Boseman's T'Challa (aka Black Panther) is one of the unsung heroes of Captain America: Civil War. Just like Lando does in Empire, he slides into the plot all suave like and you never really know whose side he's actually on. Like Lando, T'Challa is on his own side (at first) and has his own ulterior motives at play. He wants revenge against the person who killed his father at the bombing in Geneva, who he thinks is Winter Soldier. Little does he know...

And by the way... the movie excels at turning Winter Soldier into this puzzle with continual moving parts. Even if the guy is all kinds of futzed in the head and not the most charismatic of the lot (to say the least), it's captivating to watch how they use him in the movie. First it sets him up as the guy behind the big bombing that killed Panther's pops, and then it lets him off the hook only to pin the Stark killing on him at the end. It's like a double reversal, and it's great. 

But where were we? Oh yeah, Stark.

Tony Stark is Peter Parker's Yoda

While there is no old, wise green creature to help mentor our hero and teach him to find the strength to just go kick Thanos' ass already, we do have a brief nod to the Luke-Yoda relationship with Peter Parker and Tony Stark. When Stark finds Parker holed up in his hot aunt's Queens apartment, the kid realizes he has powers, but he's got a crap suit and he doesn't quite know what to do with these cool abilities he's acquired.

Cue Tony Stark, who tricks out his Spider-Man suit, throws him some pointers and then shoves him into battle. It's clear Parker still has a lot to learn -- and we're sure they'll touch on that when both Stark and Parker meet again in Spider-Man: Homecoming -- but Spidey evolves as much as Luke does in Empire, as far as powers go. He gets better at being Spider-Man -- he definitely has more sophisticated control over his powers -- but you can tell he still has a lot to learn. 

Some of the greatest sacrifices we make in life are for our closest friends.

The Empire Strikes Back opens up in a pretty dire place, with Luke captured by the Hoth Wampa and real close to being dinner that evening. Luke eventually escapes, but then finds himself in the middle of a snowy terrain that's impossible to navigate. As the sun sets and Luke's whereabouts are still in question, Han Solo risks his own life by going after his friend. (Luke, meanwhile, repays the favor at the beginning of Return of the Jedi when the roles are reversed and Han is the one trapped in ice.)

Much of the same can be said for Civil War, especially when it comes to Cap's loyalty to Bucky, and Rhodey's loyalty to Tony. The characters in this film make great sacrifices for one another -- they literally beat the crap out of their own supposed team members in order to protect their friend's beliefs. 

That's some pretty aggressive stuff, and Civil War even pushes past Empire in a way when it comes to one's loyalty to their friends, especially when that major info bomb is dropped at the end.

It includes a massive revelation that will forever change the relationships these characters have with one another

Like how Empire foreshadows its major revelation throughout, teasing a stronger connection between Darth Vader and Luke Skywalker, Civil War does the same. We continually revisit one of the Winter Soldier's kill missions through old footage of the event. We see Winter Soldier force a car off the road, and eventually we watch as he murders the two people in it.

And just how Vader delivered that shocking line to Luke in the midst of their climactic battle, Iron Man learns that, yes, it was Winter Soldier who killed his parents -- and that scene we've been watching throughout is the recorded incident in question.

And to further throw salt in Tony's literal wounds, Cap knew his buddy Bucky killed Stark's parents!

And... fight!

This isn't just another twist in just another Marvel movie. This is a game changer. Knowing Vader is Luke's father changes everything for those two characters, and their subsequent meetings are so much more personal. Similarly, once the Stark-Bucky twist is revealed, that Civil War finale becomes the most intensely brutal sequence to watch play out. As cowriter Stephen McFeely put it when I sat down to chat with him and Christopher Markus, their intention with this scene was "to hurt the audience as much as it hurts them."

When Cap brings his shield over Tony's bloodied face and two old friends stare each other down in the most menacing of ways, it is hands down the single most horrifyingly memorable moment in any of Marvel's films to date. 

The bad guy wins

One of the many aspects of Empire Strikes Back that arguably make it the best Star Wars movie to date is that the bad guys win in the end. They capture one hero, freeze him in carbonite and send him off with a bounty hunter. Then they cut off the hand of our other hero, completely destroy his soul and send him falling into some hole where he ends dangling in the middle of nowhere on the verge of death.

Credits roll, you're sad for months.

While some of our heroes manage to limp away, the audience is left with an uneasy feeling. Sure, our friends are alive on the outside, but man they gotta be all kinds of screwed up on the inside.

The same goes for Civil War. Its villain, Baron Zemo, is basically just a dude who's pissed the Avengers inadvertently destroyed his family in Sokovia. And so how does he respond? By destroying their family. Like Empire, our heroes do end up walking away from it all with their lives intact, but make no mistake -- they're broken in some pretty devastating ways. The world hates them and they hate each other... and all it does is make us even more excited to see how these additional layers add to the complexity of that two-part Avengers finale due up in 2018.

In the end, it's all about family

If there's one thing Star Wars taught us, it's that wild action sequences and dazzling special effects are cool and all, but what we're truly invested in are the characters and their relationships with one another. That's why Darth Vader's revelation -- and not, say, the awesome battle sequence on Hoth -- is so impactful and the single most memorable moment in all of Star Wars history. And once we learn the truth behind Luke's biological family, we're angry and upset more so because we're afraid of how it's going to affect the relationship he has with his new family.

The Marvel movies know how important the idea of "family" is when it comes to their films since that's a reoccurring theme throughout many of them. From Iron Man to Thor to The Avengers to Guardians of the Galaxy to Ant-Man and now Civil War, family always plays an integral role because Marvel knows that's what made Star Wars, well, Star Wars.

At the end of Civil War, Winter Soldier is put back in the freezer, unlike Han Solo who's frozen for the first time at the end of Empire. And what's interesting about these two characters being frozen at the end of their respective films is that they both kinda deserve it. Winter Soldier is a loose cannon and until they can fix the whole brainwashing thing, he needs to be contained. Solo, on the other hand, owed a debt that he never paid. It's his own fault he got the old frozen-in-carbonite punishment from Jabba the Hutt.

And once both men are sent to their respective frozen chambers, we look to who's left and we see a family in peril. We see the bad times. Back then we turned to Luke.

But now we turn to Cap.