Veronica Rossi

It's been months since Perry was named Blood Lord of the Tides, and Aria was charged with an impossible mission; now they are about to be reunited. But their reunion is far from perfect. The Tides don't take kindly to Aria, a former Dweller. And with the worsening Aether storms threatening the tribe's precarious existence, Aria begins to fear that leaving Perry behind might be the only way to save them both.

Before Perry and Aria, there was Roar and Liv.

After a childhood spent wandering the borderlands, Roar finally feels like he has a home with the Tides. His best friend Perry is like a brother to him, and Perry's sister, Liv, is the love of his life. But Perry and Liv's unpredictable older brother, Vale, is the Blood Lord of the Tides, and he has never looked kindly on Roar and Liv's union. Normally, Roar couldn't care less about Vale's opinion.

...

After sealing Sebastian in a dark dimension with the demon Samrael, Daryl loses her visions and must rely on her instincts to lead the riders into a shadowy realm where she fears she may have to use evil powers in order to rescue him.