Ruins of Sea and Souls by Lisette Marshall

“You fell in love with a fae executioner. Did you truly think that would end well?”
With war looming, Emelin’s plan is simple: break the Mother’s bindings while her more diplomacy-minded friends persuade the rest of the world to join their rebellion. Unfortunately, their would-be allies are far too concerned about Em’s exact connection to the feared and hated Silent Death.
They might risk their lives for the world’s only unbound mage, but they’ll never fight for a fae prince’s puppet.
Forced to hide the explosive secret of their love, Em and Creon journey to the plague-cursed continent to learn more about the bindings. But as they face dragons, ruins, and murderous forests in search of the vanished gods, distrust between Creon and their travel companions brings tensions to a boiling point.
And if their love may cost them the victory against the Mother … how will Em ever choose between her heart and her duty?