After some time outlining quite a complex story, I came to the conclusion I need more than one point of view to tell it all. However, I need to have one of those points of view's character as the protagonist, to make him stand out among the others, to make the reader feel this is his story.
I am aware of the traits a main character has to have in order to make for a good protagonist: Induce empathy, have bravery to try, have flaws, make him fail because of them, have a purpose, make him evolve... But I think all of those should apply as well for any well designed POV character, if one is to hold reader's interest at its best. What are the traits that would make a main character the important one?
Some things I think can influence this feeling are the order of appearence, the ambitiousness or importance of his task to the world, the amount of backstory, and how much the reader is induced to care for each one, but I am sure there is more than that.
I will use Game of Thrones as a reference here, trying to avoid spoilers though: In Game of Thrones book, where each chapter is written from a different POV and none seems more important than the rest, the story led me to feel as if Ned Stark was the main character, even when he appeared with much less frequency than others did. And, considering the ending, I think this was done on purpose.
How can that difference between him and the others be spotlighted? I know having the narrator switch between 1st and 3rd person would help, but I'm looking for more subtle ways, as I'm trying to keep everything in a 3rd person view.