Percy Jackson, Harry Potter and The Wizard Demigod war(Percy Jackson Crossover)

Percy: My sister?

Recap:

"Sorry, one more question. Why was everyone so shocked by the girl who was a daughter of Poseidon?" Hermione inquired.

" There are three main gods called the Big Three. Zeus, Poseidon and Hades. They made a pact awhile back to not have anymore children because they were too powerful. Zeus broke the pact twice and apparently Poseidon twice. Two years ago, they agreed the pact wasn't worth it and disbanded it."

"Wait, you said Poseidon broke it twice." Hermione said.

"Yup, pleased to meet you! I'm Perseus Jackson, son of Poseidon." he declared.

"So, you had an unknown sister for twelve years?" Harry asked.

"Apparently! Now, I have to go make sure she settles in and meet her. If you need anything go to the Athena Cabin I pointed out earlier." Percy said, waving goodbye.

"Thank you." Harry chimed in as Percy turned to leave.

"No problem. Goodnight!" Percy said as he took his leave. 

.............Now Onwards.............

Percy practically ran out of the Big House, eager to meet his new sister. He sprinted across the grass. Jason came up next to him. 

"You ready?" he said, knowing exactly where he was going.

"I don't know. I'm nervous." he admitted as he slowed.

"The great Percy Jackson scared!" Jason said jokingly.

"Hey!"

"Relax, you've got this! You're an amazing person. She'll see that." Jason said, hugging Percy comfortingly.

"Yeah. Thanks man."

"Anytime," Jason said, "Now go!" 

Percy stumbled forward from Jason's light shove but continued to race to Cabin 3. Stopping in front of the doorway, he caught his breath. His hand hovered on the doorknob. Taking a breath and forcing all his worries down, he walked in.

Annabeth was sitting with his sister on a top bunk bed, explaining her parentage.

"And this is your brother, Percy Jackson. My boyfriend." Annabeth said as Percy entered the cabin.

The two stared at each other for a moment. Each drinking in each other's appearances. The thirteen year old girl had dark skin and raven black tresses. Her wavy, wet, and loose hair framed her face, making her look older than thirteen. Her over-sized Camp Half-Blood shirt was more like a dress. She looked scared and confused. She hid it with a determined but wary expression. A angry red gash streaked across her cheekbone and bruises dotted her hands with hues of purple. 

"Um. Hi. I'm Nyssa." she said hopping down to greet him. Her fingers, absentmindedly, fiddling with the seams of her shirt.

"Hi. I'm Percy. Welcome to Cabin 3." Percy said, scratching the back of his head, nervously.

"Well, I have to check on my cabin. I have to make sure, no wars have started. Demigods are crazy." she joked, reassuringly squeezing Nyssa's hand. "You're in good hands."

Annabeth smiled at the young girl and then hugged Percy. "You've got this! I love you." she whispered. Kissing his cheek, she left.

"Love you!" Percy called, as she exited.

Nyssa shifted, barefoot, still fiddling with her seams. Her eyes were a dark brown, almost black color. She studied him with a wistful look as if she saw something else instead of him. Percy popped his shoes off and sat on a empty bunk, gesturing for her to sit.