Rick Riordan created these characters, not I.
Percy
Percy Jackson lay awake, listening to the sound of waves crashing against the Argo II. The ocean's calm was usually what lured him to sleep, and chased away the nightmares created by years of tragedy entwined with sadness and misery. The boy with the green eyes closed them, resting his head against the pillow.
Tonight it was hard to fall asleep. He had just battled a monster, and visions of Tartarus haunted him every time he closed his eyes. The memory of him scaring Annabeth still lurked in the deepest corners of his mind. She said it was fine. He said it wasn't.
Percy was expected to lead this quest, to lead every quest. He was expected to be perfect. He wasn't.
A moonbeam found its way through the murky ocean and filtered through Percy's window. He watched the odd shadows of bubbles and fish drift across the floor. And he wondered what he would do when the weight of the world became heavier than it was before. And he wondered what would happen when Annabeth couldn't hold it up anymore and left him to do it on his own.
Annabeth
Annabeth Chase was in a similar state of mind. She had covered the window with curtains, and was sitting in the absolute dark, listening to her own breathing. Percy had fallen into Tartarus with her—for her. She had made him, in a sense.
No, it was his choice. Don't blame yourself dear. A tiny, uncertain voice whispered in her mind. She turned and faced the wall, blinking away tears as part of her disagreed. That part of her blamed herself, and then the rest of her agreed.
It was her fault. It was all her fault.
Annabeth reached into a small bag by her bed. She pulled out a smartphone and ear-buds, plugging one into the other and finally into her ears. Turning down the screen's brightness, she opened up YouTube and listened to music. No matter what the words were, the music spoke one thing to her restless mind. "Hey, you okay sweetheart? It'll be alright. I'm here. Just listen to me."
Jason
Jason Grace. He was some people's definition of perfect. The only mark on him was from his eating a staple when he was younger. He had a daughter of Aphrodite girlfriend who could kick some serious butt when she had the chance. He was a son of Zeus, for crying out loud. He was a Praetor of New Rome.
But he wasn't. The world's expectations of him were too high. Every mistake he made, every fight he lost, they were all imprinted into people's minds. They only notice the bad things.
Isn't it funny how the world can forget every good thing you've done but remember every mistake?
Very funny. Jason wasn't perfect at all. He barely saw his older sister, and she was from a different aspect of their dad. His mother had been driven to madness because of his dad. She had abandoned him. The world saw him as some kind of amazing person when the wolves found him. But if that hadn't happened…then none of the wonderful things he did would have.
Piper
And Piper McLean was tired of the stereotypes put against her. She was pretty, so she couldn't fight. She was a daughter of Aphrodite, so she must be obsessed with boys and make-up. She was the daughter of Tristan McLean—a famous movie star—so she must be a spoiled brat.
Every time she said her name, everyone wanted something from her. She wondered why people even liked her most of the time. Was it for her looks? Was it for her dad? Was it her money? Her parentage? Did she accidently charmspeak them into it? She didn't know. She didn't want to know.
Did anyone even like her for her? Maybe so. Maybe not.
Maybe her friends were a lie. Maybe her boyfriend was a lie. Maybe this was all an intricate, fake reality that the gods set up to mess with her. Like the time she remembered that never happened. Maybe this was a replay of it. Maybe she would wake up from this dream. And maybe that would be better, better than being judged. Maybe she'd be ugly and poor. Maybe that'd be more desirable than this.
Hazel
Hazel Levesque had reached one conclusion: the modern world was extremely messed up. Every teenager in the world was hateful, whether it be to others or themselves. And that was also in the forties, when you were judged for everything from race to gender. But now, when there was this supposed acceptance, there wasn't really.
And none of that had hit her yet. So she was waiting for the moment when it would be. She rolled over in bed and remembered part of a song Nico had showed her. He said that she may like it, it was part of his mission to show her music. The only thing he was used to about the modern age was the un-popular music. He had showed Hazel Imagine Dragons. "They're technically rock, but it's not the heavy metal stuff. They're really good."
Lyrics played through her mind: I'm ready for the fall, ready for everything that I believe to come crashing down.
Maybe she'd escape that, but maybe she wouldn't. Maybe she'd just skip that. Maybe Annabeth and Piper wouldn't let her. Maybe…maybe. It was all a maybe. She didn't like maybes. Maybe her mom was just changing. Maybe she wasn't being possessed by the Greek embodiment of the Earth. Hazel laughed silently and sarcastically. Maybe.
Frank
Frank's problems were simple. He didn't want to be a child of Mars. He didn't want his life to be controlled by a twig. He didn't want his mom to have died. He didn't want to be taken away from his Grandmother, however disapproving she was towards him all the time. He didn't want to feel awkward and wrong all the time. He didn't want to feel like Hazel only liked him out of pity.
But he did feel like that. And he didn't want to. It wasn't a pleasant feeling at all, but when was it ever? What memory did he have of a pleasant feeling? The concept was foreign to Frank. Like the ideas in another country, not worrying about things like that were things that other people knew. He was with the group who did worry about it.
And he didn't want to be. He…he just didn't.
As the sun rose on the horizon, it trickled through the water and into the small room that Frank slept in. As he watched the fiery red sun appear, he could have sworn he saw a boat. It must've been Apollo's red car, bringing in the sun. But it didn't look that. So he worried about that too.
Leo
Nico
Let's just say…poor Leo and Nico. They need hugs. You already know about them. But that doesn't make them any less important. That just makes them need less explaining.