Wanda Maximoff: We wait for two days for Tony Stark to kill us.
Family can be a powerful motivator.
When the Maximoffs lose their family to a group of Tony Stark's missiles, they vow to get their revenge—and they vow to do it together. Sure, there are just two of them, and twins at that, but theirs is one of the closest family bonds (to each other and their dead parents) that we see in the film.
Laura Barton: You know I totally support your Avenging. I couldn't be prouder. But I see those guys, those gods… Clint Barton: You don't think they need me. Laura Barton: I think they do, which is a lot scarier. They're a mess.
Laura is more on the money than even she knows here. But what she doesn't know is that she's just as important as Hawkeye in this equation. It's not just his professionalism that inspires the Avengers; it's his family. They offer Hawkeye a connection to the real world that the rest of these single, dysfunctional superheroes don't have. From that connection comes a sense of perspective, a grounding that all the rest of Hawkeye's teammates could really benefit from.
Bruce Banner: I can't have this. Kids? Do the math. I physically can't. Black Widow: Neither can I. In the red room where I was trained—where I was raised—they have a graduation ceremony. They sterilize you […] You still think you're the only monster on the team?
Woah, woah, woah—slow down there, Dr. Banner. Who's talking about kids? Still, he can't stop himself from jumping lightyears ahead in his imagined relationship with Black Widow. Since they're not able to have a traditional family, he doesn't see a point in moving forward with their relationship. That seems like a strange pre-condition for love, but it's a very real one that many folks encounter. Ironically, Black Widow is in the same boat. Maybe they were meant to be together after all, just in a family of two rather than eight. Come on—superheroes weren't meant to drive minivans.
Captain America: I'm gonna say this once. Tony Stark: How about nonce? Captain America: Shut it down. Tony Stark: Nope, not gonna happen.
In any family, fights are gonna happen. As the Avengers struggle to maintain their coherence as a team, rifts like this one pop up and threaten to drive them apart. Iron Man and Captain America butt heads on more than one occasion in the film. This example—while it does feature the awesome appearance of the word "nonce"—shows a battle for control as Tony tries to jumpstart Vision behind Cap's back. Still, do these heroes have to be on the same page about everything in order to be an effective team? Does a family have to agree on everything in order to function?
Vision: We have to act now, and not one of us can do it without the others.
Leave it to Vision to drop some other-worldly, weirdly-dispassionate wisdom on his new teammates. Here he gives them "the whole is greater than the sum of its parts" bit, which can be said of any family. This message of togetherness is one that Captain America's been preaching for lo these many screen minutes, but sometimes it can help to hear the same message in a different medium—even when that medium looks like a beetroot.
Ultron: All of you against all of me. How can you possibly hope to stop me? Iron Man: Like the old man said: together.
Oh, Tony. So you were listening to Cap's lessons on teamwork. These words, coming right before the movie's climactic battle, reflect a renewed faith in the power of togetherness. This is especially striking seeing as how it comes from the Avengers' least team-oriented player. It seems that Iron Man has finally come around and bought in to the family vibe that his leader has been putting out. And thanks to all this newfound familial unity, the team is finally able to pull the plug on Ultron.