A Destiny of Dragons - TJ Klune

Sequel to The Lightning Struck Heart
Once upon a time, the wizard's apprentice Sam of Wilds got his happily ever after in the arms of his cornerstone, Knight Commander Ryan Foxheart. A year has passed, and while Sam's been captured five or six more times since then, things are pretty great. His parents are happy, Gary and Tiggy still eat sass for breakfast, Randall is somehow alive despite being older than the gods, the King rules with a gentle hand, Kevin the dragon is as gross as ever, Morgan sighs a lot, Ryan continues to be dashing and immaculate, and Sam is close to convincing Prince Justin they will be best friends forever. Life is good. Until it's not. Because Vadoma, the leader of the gypsy clan and Sam's grandmother, has come to the City of Lockes with a dire prophecy written in the stars: a man of shadows is rising and will consume the world unless Sam faces his destiny and gathers the five dragons of Verania at his side. And she brings along her second-in-command, a man named Ruv. Ruv, who Vadoma says is Sam's true cornerstone.