The Honesty of Wings - The Corvid Legacy, #1

It starts with a message. Meet me at midnight - From the minute a white-winged Avian delivers a message to Rya warning her to leave the Gray, her world is upended. Not only has a strange glowing rash appeared on her skin, the city's protective barrier, The Cap, is disintegrating. As magic wreaks deadly havoc in Gray City, Rya realizes she may be the key to saving her home. But being a hero comes at a steep price. Bray's passion for the sea is rivaled only by his love for Gem, the Sea King's daughter.
When Blue Point Island is seized by floods and a mysterious blood-like silt poisons the waters, all he treasures is threatened. Soon Bray is fighting off one attack after another, both on land and undersea. But nothing can prepare him for the disaster that looms ahead. Vale's gold wings are the envy of all and the bane of his existence. Disenchanted with his future, Vale hunts down his past and makes a discovery that just may give him the answers he seeks and a future more dangerous than he ever could have imagined. For nearly eighteen years, siblings Rya, Bray, and Vale have lived unaware of their heritage or each other.
But when a long-lost princess bearing the mythical Star Crown appears, a powerful legacy is awakened, drawing them back to one another. Amidst the chaos of mounting disasters, everything they know will be questioned, including whether the princess is the benevolent ruler legend has foretold, or something much darker.