The mod adds a ton of unique locations and dungeons that are designed to look like they came from Hyrule.
Death is the main theme in Hyrule RelicsHistory and is something that much of the books and magazines will explore, giving multiple different points of view and interpretations. It is quite practical that Hyrule has been destroyed and that the best the Dragonborn can do is avenge Hyrule by defeating Alduin. It was also emphasized quite a bit early on that there is no real way to save Hyrule.