Hero, Natasha Romanoff from Avengers (2012)

Clint Barton: [Natasha has freed him from his restraints] Tasha, how many agents did I-?
Natasha Romanoff: Don't. Don't do that to yourself, Clint. This is Loki. This is monsters and magic and nothing we were ever trained for.
Clint Barton: Loki, he got away?
Natasha Romanoff: Yeah. Don't suppose you know where?
Clint Barton: [Shakes head] Didn't need to know. Didn't ask. He's gonna make his play soon though. Today.
Natasha Romanoff: We gotta stop him.
Clint Barton: Yeah, who's "we"?
Natasha Romanoff: [Shrugs] I don't know. Whoever's left.
Clint Barton: Well, I... if I put an arrow through Loki's eye socket, I'd sleep better, I s'pose.
Natasha Romanoff: Now you sound like you.
Clint Barton: But you don't. You're a spy, not a soldier. Now you want to wade into a war. Why? What did Loki do to you?
Natasha Romanoff: He didn't, I just...
[pauses]
Clint Barton: Natasha.
Natasha Romanoff: I've been compromised. I got red in my ledger. I'd like to wipe it out.

- Natasha Romanoff from Avengers (2012)

Hero, Loki & Natasha Romanoff from Avengers (2012)

Loki: Your world in the balance and you bargain for one man?
Natasha Romanoff: Regimes fall every day. I tend not to weep over that, I'm Russian... or was.
Loki: What is it you want?
Natasha Romanoff: It's really not that complicated. I've got red in my ledger, I'd like to wipe it out.
Loki: Can you? Can you wipe out that much red? Drakov's daughter, Tugenov, the hospital fire? Yes, Barton told me everything. Your ledger is dripping, it's gushing red, and you think saving a man no more virtuous than yourself will change anything? This is the basest sentimentality. This is a child at prayer... PATHETIC! You lie and kill in the service of liars and killers. You pretend to be separate, to have your own code, something that makes up for the horrors. But they are a part of you, and they will never go away!... No, I won't touch Barton. Not until I make him kill you! Slowly, intimately, in every way he knows you fear! And when he wakes, he'll have just enough time to see the work he's done, and when he screams, I'll break his skull! This is my bargain, you mewling quim!
Natasha Romanoff: [fearfully] You're a monster!
Loki: No, you brought the monster.
Natasha Romanoff: [back in normal state] So, Banner... that's your play.
Loki: What?
Natasha Romanoff: [on intercom] Loki means to unleash the Hulk. Keep Banner in the lab, I'm on my way. Send Thor as well.
[walks out]
Natasha Romanoff: [to Loki] Thank you for your cooperation.

- Avengers (2012)

Hero, Scarlett Johansson as Natalie Rushman from Iron Man 2 (2010)

Natalie Rushman: I need your impression.
Tony Stark: Well, you have a quiet reserve about you...
Natalie: I meant your fingerprint.

- Scarlett Johansson as Natalie Rushman from Iron Man 2 (2010)