Hades' Heron (a PJO/HOO Fanfic)

As it turns out, Nico is only the second most miserable child of Hades. His half sister, Phoenyx, takes the cake. She's been through pain no one can even imagine. Its a wonder she's not insane. Or is she . . . She, Nico, and several other demigods must reveal the hidden menace in the shadows, threatening to do what was thought impossible: kill a god.

"A faint glow emanated from the tattoo. Words were written in a spiraling pattern, getting smaller and smaller as they curled into the center. Even still the words were clear: Your warning is the meeting of another/ Thy saving grace is the blood of a brother /Then Hades' Heron will fail and the Ghost King smother/ And as dust to dust, both will fade to the Nether"