How does the opening sequence establish narrative?
The opening in the Dark Knight establishes narrative by creating a catalyst in which the hero will be introduced (Batman). The scene also shows the main villain of the film (the Joker), giving the audience an idea of his intelligence and cunning when he tricks all his 'followers' into killing each other leaving him with the loot. This scene also establishes that the narrative will contain violence and criminal behavior with the villain acquiring a large amount of money.
How does it establish character?
The scene establishes the character (the Joker) as immoral. He is portrayed as evil, cunning and highly intelligent. With the theft of a highly protected bank being his plan it also shows his self confidence in his criminal ability, he comes off as arrogant. The Joker's ability to rob a bank of that stature with such efficiency shows his criminal instincts and abilities. The end of the heist shows his ruthlessness planting a grenade into an employees mouth and driving off in the bus which in turn triggers the grenade and kills the man.
