In the Shadow of Lightning by Brian McClellan
In the Shadow of Lightning started with a powerful prologue, a battle scene that introduces our main character, Demir Grappo, and gives us insight into both his personality and his power. Then we skip nine years. Demir's mother has been killed and as her heir, he returns to the city to take the reigns of the family and to find out who ordered the attack. And there's a war going on, sparked by his mother's assassination.
The magic is based on godglass. Different types of glass can give people enhanced abilities or cause restrictions. Wit glass for example makes one think quicker while shackle glass will allow the wearer to only tell the truth. Most everyone can use the glass, although there are some who are immune to its effects. I like that about the magic, everyone has access - if you can afford it. There are also glassdancers who can manipulate plain glass, mostly using shards of it to kill...