Seasons of Chaos by Elle Cosimano

Perfect for fans of Holly Black and Victoria Schwab, this is the stunning conclusion to a lush, high-stakes fantasy duology, the first book of which New York Times bestselling author Jennifer Armentrout called "flawless and addictive."
As immortal Seasons, Jack and Fleur wielded powerful magic in their roles as a Winter and a Spring. Yet there wasn't magic strong enough to keep them apart, and they risked everything for their love, for the freedom to live their lives as they choose-together.
That choice came at a cost, and Jack had to sacrifice his Winter magic-and his immortality. Although he'd do anything for Fleur, he can't deny the emptiness he's felt since.
And the world they thought they left behind is still dealing with the fallout of the battle. With Professor Lyon as the new Chronos, Seasons are free to do as they please. But not everyone is happy with the change in leadership. When an old enemy seeks revenge, immense magic runs wild and unchecked, creating chaos everywhere.
Thrust into the middle of a new war, Jack and Fleur are again forced to choose between their freedom and saving the world from the storm.