The Lost Sun came very close to being thrown into my DNF pile, but I managed to trudge through it....barely.
I'm a huge fan of mythology, although I'm not as familiar with Norse legends and myths. This is a book that should have worked for me. Instead, it was a huge letdown. To put it bluntly, the world-building in this book needed a "hel" of a lot more attention. The characters live in some alternate version of American society called the United States of Asgard, which is a land inhabited by Norse gods and goddesses. We aren't told how or when this happens and you could argue that this book is a work of fiction, so I should just go along with it. Believe me, I tried.
Asgard is divided into "kingstates" which I would assume are ruled by a king or royalty of some sort. Kings are alluded to, but remain unnamed. We know there are wealthy politicians who hold power, but there's no mention of nobility or royalty. The closest described are the gods and goddesses. Are these the "kings" that rule? Perhaps. Again, we don't know for sure and your guess is as good as mine. The United States of Asgard also has a lawspeaker, a President, and a Congress. Are you still following me? Good, because it only gets more confusing. We are also given a long list of geographic locations within Asgard which sound vaguely familiar, territories referred to as Nebrasge, South Lakota, Vertmont, Colorada, Cantuckee, Missoura, Mishigam, and Canadia. Oh, and the White House is now the White Hall and students study Anglish instead of English. Now I know that if I want to write a story set in a mythical land, all I need to do is insert or delete a letter from a word that already exists and then the world-building is done for me. I don't need to do any work whatsoever to describe the setting or how this world came to be.
For example, I could write a story about the fae who are forced to live among humans in futuristic Europe, let's say in the territories of Frunce and Germano. The names explain themselves - I don't need to specify anything else about why the fae are there. It simply exists. The end.
From a linguistic perspective, The Lost Sun was extremely painful to read. The vocabulary is so distracting that I found myself more focused on locating ridiculous word choices rather than caring about what happens to the characters in the story. I won't even comment about the quest Soren and Astrid set for themselves or how every action they take was determined by fate. You could randomly pick a page in the book and the odds are good that you will find the word "destiny" or "fate" stamped on it. This theme is not exactly subtle, nor is the idea that Soren and Astrid are meant for each other.
I'm sorry, but this book lacked execution and it just doesn't work for me. So disappointing.