Could someone give me pointers on 글쓰기 a prophecy for a Percy Jackson fanfic?

I swear, it's not a cliché 랜덤 person saves the entire world.
Okay it's a little cliché.
But nothing can be completely original!
Anyways, I plan this to be a trilogy, and because I am an indecisional person, I decided to plan out all the 책 before I begin writing. I wrote this great prophecy for the first book:
Two children of magic, of darkness and choice,
A thief and a lord, with the power of voice,
The dawn cries out, for herself she must fend,
The sire of winged 말 당신 must tend
Yeah, a little help on the end of that one too...
But I need a prophecy. It's a Percy Jackson Harry Potter crossover, and it involves them fighting. No Nyx is rising stuff. Like a Civil War. But I need pointers. Help please!
P.S. 16 people are going
P.P.S From the Seven, only Caleo, Piper, and Hazel are going.
P.P.P.S Canon characters going are: Caleo, The Stolls, Katie, Piper, Hazel, and Solangelo

Percy Jackson, remember that!