So one of the things Brandon Sanderson does best is build up a magical world on logical principles, not tell those principles to the reader, and then make discovering those principles drive the plot of the series. Brandon Sanderson’s Calamity, and really the whole Reckoners trilogy of which this is the third book, is a perfect example of that approach.
As I read the first two, I liked the mystery setup, but was unsure whether he could actually resolve all the mysteries in the third book. The good news is, he was able to. By the end of the book, everything is wrapped up in a way that’s relatively satisfying. The better news is, this series really is self-contained and not part of Sanderson’s horrifically misconceived Cosmere multiverse, so you don’t have to worry about another book coming along later and retconning this into being about shards and investiture and a bunch of other meta-series nonsense.
Taken as a whole, the Reckoners trilogy isn’t super-great or revelatory or anything—but it’s decently enjoyable superhero-flavored fantasy, so worth reading if you’re looking for a satisfying quick read.