Dark Angel Chronicles Series by Melanie Nilles

They've been coming here for thousands of years, using Earth as a sanctuary to escape threats from their own kind. Mankind knows them as angels, and one of them left a child upon her death to be raised as a human. Raea is now a high school senior, and her life as a human is about to end... moreThey've been coming here for thousands of years, using Earth as a sanctuary to escape threats from their own kind. Mankind knows them as angels, and one of them left a child upon her death to be raised as a human. Raea is now a high school senior, and her life as a human is about to end. The crystal shard she bears is not a pretty pendant; it's a collective of powerful entities who chose her as their Keeper, a protector of one of the four shards that power a machine capable of destroying whole worlds. Those who desire the Starfire's power have sent an agent to find her, but she's too busy evading a nosy reporter ready to exploit her secret and dating a hot new foreign student to notice. Nevermind learning what she really is. Only one person on Earth can help her, the last person she ever expected. But he's not from Earth. Life as a human would be so much easier. less

One Shirukan, an elite soldier of the Shirat Empire, came to Earth for Raea's Starfire shard and failed. Aware of the possibility of another attack, Raea trains to use the shard's power to protect it while preparing to graduate from high school. But she discovers that the Keeper training her has betrayed her trust and must decide where her heart belongs. She never imagined that distance from him would mean a universe apart... moreOne Shirukan, an elite soldier of the Shirat Empire, came to Earth for Raea's Starfire shard and failed. Aware of the possibility of another attack, Raea trains to use the shard's power to protect it while preparing to graduate from high school. But she discovers that the Keeper training her has betrayed her trust and must decide where her heart belongs. She never imagined that distance from him would mean a universe apart. After the Shirukan attack, she wakes up on the Inari homeworld among those whose loyalties she questions. To return home, she must reach the Crystal Keeper known as Saffir. First, she must elude the thousands of Shirukan between her and freedom. less

The Shirukan aren't the only threat to the Starfire shard Raea bears... An alien enemy has awakened to reclaim the crystal that was theirs, and those last survivors of a war that nearly destroyed Inar'Ahben aren't afraid to kill anyone who stands in their way. An ancient monument to a mythical civilization on Earth may hold the key to stopping the new enemy, if the secret of its origins can be unlocked... moreThe Shirukan aren't the only threat to the Starfire shard Raea bears... An alien enemy has awakened to reclaim the crystal that was theirs, and those last survivors of a war that nearly destroyed Inar'Ahben aren't afraid to kill anyone who stands in their way. An ancient monument to a mythical civilization on Earth may hold the key to stopping the new enemy, if the secret of its origins can be unlocked. Raea is running out of time to solve the most puzzling question of human history and resolve the conflict brought to Earth. If she fails, she may lose more than the Starfire... less

Before he became the Dark Angel of McClarron, North Dakota, Elis had a life on his homeworld of Inar'Ahben…or tried to. A younger brother tormented by his older sister. A Keeper hunted by the Shirukan. A best friend betrayed. And a survivor sent alone to Earth to protect a shard of the Starfire crystal. For Elis, peace was only a word. Every story has a beginning. This is the beginning of Dark Angel…

It's a final showdown for control of the Starfire. Raea and Elis's bond is strong, but the Shirukan intend to use it to force her hand to give up the Starfire shard. To complicate matters, a shadow from Elis's past has returned, claiming to help; but when he betrays Elis to the Shirukan, Raea must figure out whom she can trust before it's too late. All of Inar'Ahben is counting on them to keep the Starfire out of the wrong hands, but the Starfire has other ideas... moreIt's a final showdown for control of the Starfire. Raea and Elis's bond is strong, but the Shirukan intend to use it to force her hand to give up the Starfire shard. To complicate matters, a shadow from Elis's past has returned, claiming to help; but when he betrays Elis to the Shirukan, Raea must figure out whom she can trust before it's too late. All of Inar'Ahben is counting on them to keep the Starfire out of the wrong hands, but the Starfire has other ideas. They leave Raea with only one choice-make the ultimate sacrifice or risk losing everything to the Shirat Empire. less