We go from this: [spoiler]"The Darkness is coming back. We will not survive it this time." (Speaker Introduction)[/spoiler] To this: [spoiler]"For centuries we feared the forces of darkness massing against us. We sought to hide and cower beneath a broken god. No more. These guardians show us what we are, what we have always been, and what we will be again. We are what remains of the light and we will not be stamped out." (Speaker - End speech)[/spoiler] Not even looking at anything else in the story your actions as a guardian result in this change. There are a lot of things that are affecting by what you do in the story. It's not affected in the way that you would have a different outcome of the story like in a Mass Effect game but there are cause/effect situations in the story.