Thor: Loki is beyond reason, but he's of Asgard and he's my brother.
Black Widow: He killed 80 people in 2 days.
Thor: He's adopted.
Captain America: So, Thor, what's his play?
Thor: He has an army, called the Chitauri. They're not of Asgard nor any world known. He means to lead them against your people. They will win him the Earth, in return, I suspect, for the Tesseract.
Captain America: An army, from outer space.
Thor: You have no idea what you're dealing with.
Tony Stark: Uh, Shakespeare in the park? Doth mother know you weareth her drapes?
Loki: ENOUGH! You. All of you are beneath me. I am a god, you dull creature, and I will not be bullied by...
[The Hulk grabs Loki and slams him into the floor repeatedly.]
Hulk: Puny God.
Loki: I have an army!
Tony Stark: We have a Hulk.
Natasha Romanoff: I'd sit this one out, Cap.
Steve Rogers: I don't see how I can.
Natasha Romanoff: These guys come from legend, they're basically gods.
Steve Rogers: There's only one God, ma'am, and I'm pretty sure he doesn't dress like that.
Tony Stark: I thought we were having a moment.
Pepper Potts: I was having 12% of a moment.
Tony Stark: You know, you should come by Stark Tower sometime. Top ten floors. All R&D.
Bruce Banner: Thanks, but the last time I was in New York, I kind of broke Harlem.
Tony Stark: Dr. Banner, your work is unparalleled. And I'm a huge fan of the way you lose control and turn into an enormous green rage monster.
Bruce Banner: Thanks.
Captain America: Dr. Banner. Now might be a really good time for you to get angry.
Bruce Banner: That's my secret, Cap. I'm always angry.
Nick Fury: You think you're the only hero in the world?
Pepper Potts: Is this about the Avengers? Which I know nothing about.
Tony Stark: The Avengers initiative was scrapped, I thought. And I didn't even qualify.
Pepper Potts: I didn't know that either.
Tony Stark: Apparently I'm volatile, self-obsessed, and don't play well with others.
Pepper Potts: That I did know.
Steve Rogers: Stark, we need a plan of attack!
Tony Stark: I have a plan: attack!
Captain America: Barton, I want you on that roof, eyes on everything, call out patterns and strays. Stark, you got the perimeter. Anything gets more than three blocks out, you turn it back, or you turn it to ash.
Iron Man: Got it.
Hawkeye: Mind giving me a lift?
Iron Man: Sure. Better clench up, Legolas.
Maria Hill: Director Fury, the Council has made a decision.
Nick Fury: I recognise the Council has made a decision, but given that is a stupid-ass decision, I've elected to ignore it.
Steve Rogers: You think Fury is hiding something?
Tony Stark: He's a spy. Captain, he is the spy. His secrets have secrets.
Black Widow: This is just like Budapest all over again.
Hawkeye: You and I remember Budapest very differently.
Tony Stark: Falling in line's not really my style.
Steve Rogers: You're all about style, aren't you?
Thor: You people are so petty, and tiny.
Nick Fury: Having trouble sleeping?
Steve Rogers: I've been asleep for 70 years, sir. I think I've had enough rest.
Steve Rogers: You think you can hold them off?
Clint Barton: Captain, it would be my genuine pleasure.
Answer: While Loki is not immortal, he's just as powerful as Thor, and many mortals would consider him a God as well. Loki is actually a Frost Giant taken in by Odin, but is just as invulnerable to many attacks. There may also be an element of magic involved in his survival as well.
Bishop73