Little Brother Percy Winchester

Threats

They found Grover pacing in the record room.

"You're back?" he asked. Dean marched up to the dungeon wall. "Wait, you really don't want to go in there!"

Dean ignored him, making a beeline inside the dungeon for the figure chained inside the pentagram.

Percy's head was down, but as soon as Dean stopped, he looked up, his yellow eyes smirking at his brother.

"Hello, Dean," he greeted, "Did you enjoy your trip to Hell?" His eyes became sea-green again.

"You're not my brother," Dean growled. Annabeth entered behind him.

"I am very much your Squirt as I am her Seaweed Brain," Percy said, doing jazz hands. He sighed. "I do agree that the yellow eyes aren't a good look on me, buut-" Thalia slapped him. "Ouch, Pinecone Face."

"Explain," Thalia's voice shook as Annabeth moved to her side.

"I'm a Prince Of Hell," Percy grinned, avoiding Annabeth's glare. "The Mark of Cain prevented my death, allowing me to continue my mission."

"Your mission?" Dean questioned. Percy shook his head, laughing.

"Like I'd tell you."

"Does it have to do with Deamon?" Sam asked. Percy raised an eyebrow.

"I'm surprised you remembered. That was part of human me's motivation, but not anymore."

"You knew you wouldn't die," Annabeth whispered. "You knew-"

"I'm sorry," Percy whispered, so only Annabeth could hear. He met her gaze, then spoke louder. "None of you could have stopped me anyway."

"You murdered Zeus," Thalia accused. 

"The Olympian Council was so surprised to see their hero murder that dick," Percy laughed, "As was Chiron when I took Will. Camp is safe, just so you know. For now." 

"I hate you," Thalia said horrified. She left, passing by Grover who was just entering, carrying a syringe.

"C'mon, G-man. I've been nice!" Percy complained, eyes trained on the syringe. "It's not going to work. You're going to end up killing me."

Grover didn't respond, jabbing Percy in the neck. Percy grunted, and blinked, allowing his eyes to become yellow again.

"You're not going to like me when this is over!" Percy roared, his voice dropping octaves. Grover removed the syringe and began walking away. "I'm going to murder all of them, and make you watch!" Grover paused, and turned to face him.

"You left me instructions," he said slowly, "You know exactly how this is going to work, and it doesn't end well for you." Then, Grover left.

Curious, Sam followed. Will dragged Nico out with him, leaving only Annabeth and Dean.

"He's curing you?" Dean asked incredulously. Percy didn't respond.

"That's possible?" Annabeth turned to Dean. Percy had to grit his teeth to prevent himself from screaming in pain.

"Well, my brother almost cured Crowley," Dean shrugged, staring at Percy. "We will cure him."

"I'll kill you all," Percy threatened, fighting against his restraints. "Starting with Camp." His eyes shifted back and forth. Sea-green to yellow and back again.

That's when Dean left, followed by Annabeth. They locked Percy in the dungeon and joined the others in the kitchen.

"What are we doing to Percy?" Sam asked, looking at Cas first before glancing at Grover, who was messing with Percy's tablet.