AN: This one is written for the prompt "scars," focuses on Nya, and takes place before even the pilots.
Nya had learned a lot of things: how to talk, how to walk, how to dress herself, how to feed herself, how to make friends, how to make change for customers. But the one thing Kai refused to let her learn was how to create the things they sold. She begged him over and over, but he wouldn't give in.
"C'mon, Kai, you've been doin' it for years, why can't I?" Nya would plead.
"Because I say so, and I'm in charge," Kai would say stubbornly, and then he'd take all the tools that Nya had been eyeing and keep them with him even when he wasn't actually using them so that she couldn't sneak them away and figure out how they work. He would even lock the furnace and the cabinets holding their metal shipments and keep the keys in his pocket.
Finally, Nya actually got a real answer out of him after she'd prodded and poked him all day, both with words and with whatever she could find, from her own hands and feet to the broom and dustpan. She prodded and she poked and she pestered and pestered and pestered, and eventually Kai shouted out, "Because you're my little sister and I'm s'posed to protect you!"
Nya stared at him, then she burst out laughing. Putting down the broom she had been poking her brother with, she asked, "Protect me from what?"
"From, you know. The fire and the hammers and the, the, the weapons and all that," Kai said.
"And when have you ever got hurt from that stuff?" Nya wondered.
Kai had to stop and think about it for a moment. "Uh... I haven't, not in a while, but when I was teaching myself based on everything Dad ever said, I burned myself and cut myself a bunch."
"But I won't be teaching myself. You'll be teaching me. And I won't burn or cut myself, I know better than that," Nya stated. Before Kai could get mad over the fact that she acted like she knew more than he did, she added quickly, "I won't get hurt, 'cause you never get hurt."
"One day I'm gonna get hurt, you know that, right?" Kai asked. "Blacksmithing isn't easy."
"'Course it isn't. Doesn't mean I can't do it, so when can I learn?" Nya insisted, slowly and teasingly picking up the broom and brandishing it at him again.
Kai batted the broom away and told her, "Never."
"Maybe one day?" Nya pleaded. "Maybe maybe maybe? Maybe maybe maybe maybe maybe maybe maybe maybe-"
"Fine, whatever. Maybe one day," Kai said over her, turning away.
Nya grinned.
"But I don't think 'one day' is ever gonna come," Kai muttered under his breath. "Ow!"
Nya had poked him in the back with the broom, hard. "Heard that!"
Unfortunately for Kai, 'one day' came just a few days later, when Kai was working on a new shovel for one of the local farmers. Nya was tossing a ball up in the air and catching it and tossing it and catching it over and over while she watched for customers, so she didn't see exactly what happened, but she heard a soft thud, then a yelp, then a much louder thud and a clatter.
Nya caught her ball one more time, then she turned to see what Kai was fooling around with that was making those noises.
The ball fell out of her hand and rolled away, completely forgotten as Nya stared in horror.
Kai lay sprawled across the floor on his back.
The shovel head he had been presumably carrying across the room was next to his head.
Blood was gushing from his face.
Nya didn't know how long she stood there, staring in shock and panic, before she shook out of her daze and rushed to her brother's side, but it felt like an eternity.
Running to kneel next to Kai, Nya thought quickly. What was she supposed to do? Well, when she scraped her knees after falling while playing Tag, Kai had cleaned her up and put pressure on the gashes before bandaging them up. She guessed something similar would be the best idea.
Nya hurried to the bathroom and wet down a washcloth, grabbing the whole box of bandages. It had been hard to tell with all the blood how much he was actually cut, so the more bandages, the better. Running back to Kai, Nya began wiping his face with the wet washcloth, sticking out her tongue as she concentrated on getting her brother's cuts cleaned and pressed on. The blood slowed from a gush to a flow to a trickle finally to an ooze from the cuts, but Nya wasn't so worried about that now that she'd seen what the damage was.
The cuts went right over one of Kai's eyes. Would his eye be okay? More importantly, why wasn't he moving? Was... Was he dead?
For several heartbreaking, stomach-clenching moments, Nya was certain she no longer had a brother, then she caught sight of his chest, which was rising and falling steadily. So he was alive. ...For now. She faintly remembered something from a movie she'd once seen that when somebody's head got hurt, that was a lot harder to heal from when other parts of the body got hurt. Would Kai stay alive? Would he recover? Would he be okay?
Nya started to tremble, and tears began seeping from her eyes, but she kept cleaning her brother's face until the blood was barely even coming out, then she began bandaging Kai's head. She went around and around with the bandages she'd grabbed until there were no more bandages left in the box. Then she sat and waited, watching her brother's chest rise and fall, rise and fall, rise and fall.
"I'm sorry I stepped on your toy car and broke it," Nya said miserably. Kai couldn't hear her, he wasn't awake, so she didn't know why she was talking to him, but she kept going. "I'm sorry I called you a stinky-pants for not letting me have more dessert. I'm sorry I borrowed your favorite pants and got a hole in one of the knees. I'm sorry I stole your toothbrush and pretended it was a sword and accidentally dropped it in the mud. I promise, I'm gonna be the best little sister ever from now on, but you gotta wake up. You gotta wake up. I'm not allowed to make the stuff for the store, remember? You still have to teach me that. You have to teach me, so you've gotta wake up. You've gotta! You've gotta, you've gotta-"
"...Nya?" A voice mumbled, interrupting her. Kai!
Nya's eyes flew from Kai's torso to his face. His unbandaged eye was open, and it was looking at her.
"Kai!" Nya practically sobbed, and she engulfed him in a hug.
"Nya," Kai groaned weakly. "I got, I got a question for you."
Nya nodded tearfully. Anything he wanted, she'd agree to it, because he was alive and he was gonna be okay. "Uh-huh?"
"Did you really drop my toothbrush in the mud?" Kai asked.
Oh.
"Uhhhhh. Yeah," Nya admitted.
Kai snorted. "So that's why it was so dirty yesterday. I thought there'd been a dust storm inside the bathroom. You dropping it in the mud makes a lot more sense."
Nya laughed a little through her tears, and when Kai started moving to sit up, she helped him get seated.
"Why's my head hurt so much?" Kai asked. "I'm guessing that's why it's all bandaged up, but I don't know why it hurts."
"I think you tripped on something, and then you fell, and the shovel head you were carrying over to the workbench flew up in the air and fell down on your face. You got all cut up. I thought you were gonna die!" Nya exclaimed.
Kai looked down with his unbandaged eye at the shovel head next to him. "Huh. Back of my head hurts too, but that's gotta be from falling. And you got me all covered it bandages?"
Nya nodded.
"Good job," Kai praised, grinning, then he grimaced. "Ooo, that hurts, smiling hurts, not gonna do that again any time soon. ...Not gonna be doing much of anything again any time soon, I guess. It'll be hard to do things with only one eye not covered in bandages."
"So how are we gonna keep the store going?" Nya wondered. "We've got orders that aren't done, and there's gonna be more before your face gets better, I bet. What do we do?"
Kai looked at her. "If I could smile without hurting myself, I'd be smiling right now. Do you still wanna learn how to blacksmith?"
Nya's eyes went big and round. "Really?"
"Really," Kai confirmed. "We can start right now. Bring the shovel head over to the workbench, then come back here and help me get up."
In the next few days, Kai taught Nya everything he knew about making weapons and armor and all the other things their shop supplied. Soon enough, Nya was able to take his bandages off, and thankfully, Kai's eye was fine. Kai himself was fine as well, with only some of the cuts scarring. Nya was okay too, but sometimes she found herself watching Kai closely, making sure his chest was still rising and falling, making sure his eyes were still darting around, making sure Kai was still alive and well. The experience of thinking she had lost her brother had terrified her, and she knew she would never forget the fear that had coursed through her in those few moments when she wasn't sure if Kai would make it. It would stay with her forever as a deep inner scar.