Steve Rogers: Stark, are you seeing this?
Tony Stark: Seeing, yes, still working on believing.
[Tony place his hand over his left eye and looks at some monitors.]
Tony Stark: How does Fury even see these?
Maria Hill: He turns.
Tony Stark: Sounds exhausting.
Steve Rogers: I think Loki is trying to wind us up. This is a man who means to start a war, and if we don't stay focused, he'll succeed.
Clint Barton: The Cube is a doorway to the other end of space, right? Doors open from both sides.
Maria Hill: When did you become an expert on thermonuclear astrophysics?
Tony Stark: Last night.
The Other: The Tesseract has awakened. It is on a neutral world. A human world. They would wield its power, but our ally knows its workings as they never will. He is ready to lead. And our force, our Chitauri will follow. The world will be his, the universe yours, and the humans, what can they do but burn?
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