Another something different! Here's a cute little fluffy headcannon idea I found on Tumblr, of what would happen if Jason tried to teach Thalia how to fly! Enjoy!
"C'mon Thalia," Jason protested, trying to make his expression innocent and pleading. "It'll be fun!" In response, his sister bit her lip, arms crossed over her chest while she nervously eyed her brother, hovering around ten feet above her head.
The sun was low on the horizon as it hit the hills of Camp Half-Blood, falling on a lone pine tree next to two people. It looked like an ordinary day, except for the fact that an argument was going on. Ever since Thalia could remember, she was terrified of heights. Deathly scared. Like, oh-my-gods-I'm-going-to-die, petrified. Yeah, she knew. Daughter of the Lord of the sky, and she was so afraid of heights that she avoided them at all costs. It made no sense, but it was what it was.
"Jason," she protested weakly, shifting anxiously from foot to foot as he pouted, that adorable little scar he'd had on his lip since he was two sticking out. It made him seem ages younger, somehow, even though he was now older than her, physically at least. Thalia was forever frozen at just under sixteen, at least as long as she served her mistress, the goddess Artemis. As soon as she broke her pact, which all of the hunters seemed to eventually do, she would age normally again.
Her once younger brother was now two years older than her, and over a foot taller. Man, on some days that scared her to no end. He was growing up on her. But, what she lacked in height she more than made up for in attitude, and anybody who knew her was well informed that she was not one to cross when angry. Percy had learned that the hard way, having been blasted by lightning more times than he cared to admit. Even he was still getting older, taller than anybody else at camp. Hell, Nico diAngelo, the little scrap of a boy that the two of them had saved years ago, was starting to catch up to her, hovering around her height.
She didn't even realize that she had zoned out, only snapping out of it when she heard Percy's laughter approaching behind them. "You're fighting a losing battle there, Grace!"
Turning around, she scowled at the son of the sea god, her hands falling to her hips as she glared at him. In response, he only flashed her a crooked grin, his arm falling to rest around the person's shoulders next to him. A quick glance told her that it was Annabeth, his girlfriend of two years and her best friend of eleven. Annabeth smiled at her sympathetically, elbowing her boyfriend for being rude, which didn't faze him in the slightest.
Percy turned to Jason. "She too scared to get up there?"
Thalia's eyes flashed in anger. Nobody implied that she was a chicken and got away with it. Before she even knew what was happening, she was floating in the air next to Jason, to the shock of everybody there, including herself. "Oh gods!" she yelled in terror, her hands grasping at the air around her in an attempt to stabilize herself. "Oh sweet Zeus!"
"Hey!" Jason yelled at her, scooting close enough to seize her wrist, adding his powers to hers until they both felt like they were standing on a platform of solid air. "Hey! Chill, Thals, I got you!"
She clung to him in fright, her blue eyes wide as she looked down, immediately wishing that she hadn't. Her stomach churned, and she squeezed her eyes shut against the nausea that rose in her closed throat. Jason was her lifeline, keeping her from going into an all-out panic attack. She didn't think that she had ever been more afraid in her entire life, even during the Second Titan War, fighting for her life while her friends might've already lost. What they told you about irrational fears was true, she supposed. They made no sense, but that didn't stop them from being terrifying.
"Okay, now listen to me, Thalia," Jason soothed her, taking his other hand and turning her to face him. Her heart beat wildly in her heart, but she forced herself to listen to him. Jason was an expert on flying, having been doing it for years. If anybody knew what to do, it would be him. "I'm going to let you go, and you need to stay calm. If you want to go down, you can slowly head back towards the ground, alright?"
"What!" she shrieked, but he was already letting go of her hand. Instantly, the air liquefied, and she felt herself starting to sink, albeit slowly, but sinking all the same. Thalia let out a scream of pure terror, her arms spinning wildly in the air as she gained speed. Below her, she could see Percy and Annabeth watching, probably trying not to laugh as she tumbled towards them. Logically, she knew that nothing bad would happen to her, but her brain was past logic at the moment. All she could think about was not dying, and she squeezed her eyes shut as terror overtook her brain.
Suddenly, she was still. When she opened her eyes, she was floating on the wind, bobbing gently. Thalia felt the fear in her stomach fade slowly, and she even managed to let out a little strangled laugh, her hair in her eyes. A smile lit up her face as she closed her eyes, feeling free and weightless. At least until Percy decided to be a smartass, and threw a pine cone from the ground at her, hitting her in the leg. Her concentration broke, and suddenly she was falling again, her eyes flying open in fear as she choked on a scream. "No! Up!"
That seemed to be the magic word, and she raced upwards, no longer falling. Unfortunately, she was so shocked that it had worked that she lost control of the winds, and she got tossed sideways as the currents came back to their senses once more, gusting around her. Thalia yelled as she tumbled towards her old pine tree, smashing into the upper branches with a dull thud, branches snapping and leaves flying into the air. For a second, it looked like she was going to be stuck up there, until the branches gave out, that was.
"Ow, ow, ow, ow!" she yelled, falling through the thin branches that couldn't support her weight, hands scrabbling at the bark to try to stop her fall. She found no purchase, and even the bigger branches at the bottom didn't stop her, although they did slow her down. With an oof of more embarrassment than pain, she landed on her back at the base of her tree, head spinning, pine needles in her hair and her tiara crooked.
Annabeth and Percy rushed towards her, and she groaned as Jason flew over to her, landing at her side in an instant. Percy was pale, looking guilty as hell. Worry was on all of their faces until they realized she was okay, and then Percy burst into laughter, doubling over as tears ran down his cheeks. Thalia scowled at him, and with Annabeth and Jason's help, got to her feet. She looked down at her cousin in distaste as he rolled around on the ground, but the look on his face was so hilarious that she couldn't help but laugh too, and soon Annabeth and Jason joined in.
That said, that was the last time she tried flying….. at least for a good long while.
Prompt: Jason decided after the Giant War to teach Thalia how to fly. She did okay, floating in midair with her eyes closed, until Percy threw a pinecone at her. She screamed, shot into the air, and crashed into her pine tree. Percy nearly peed himself laughing.