A/N: Posting this separately from my Rivetra collection because I might write more in this AU someday and not everyone has watched ATLA so yeah. Let me know if you'd like to see more. Also this is rated T because Levi says the f-word once lol. ALSO sorry for the crappy title. I suck at story titles.

She watches him concentrate, brow furrowing as sweat drips down his bare back and he raises his arms, breathing in and out slowly, shifting his stance, before his feet move suddenly and he punches outward, a stream of flame hurtling towards Levi—

—who blocks it with one hand without looking up from the scroll he is perusing. "Again," he says, tone bored.

Petra sees the frustration in Eren's eyes, the exhaustion in his limbs and the struggle in the way his hands clench and unclench by his sides. "I—"

"Again."

The Avatar takes a deep breath and does as he's told, closing his eyes and feeling the fire within as all his lessons with Levi have drilled into him. He lifts his arms, settles into the correct position, turns and pivots, punches out—

—and Levi flicks his hand briefly to dissipate the waves of flame, still not looking up. "Again."

Eren drops to his knees, breathing heavily, palms on the ground and back hunched in defeat. "Sifu, I can't—"

"You think the Fire Nation'll give you a break?" Levi's eyes stay on his scroll but his tone is suddenly much harder. "You think you can say to the Fire Lord I'm tired, I can't do it anymore and he'll just go oh sure, I'll go back to my palace and kill you another day; I'll wait until Sozin's Comet has passed, until you've spent as long as you need mastering the elements to fight you—no he won't, so do it again. Now."

"No. Eren, go take a break."

Levi finally looks up to scowl at her; she scowls right back. "Petra—"

"Eren, you did well. Take a break." She offers the boy her warmest smile and his lips twitch back hesitantly, but he steals a nervous glance at Levi and Petra sighs.

"It's fine, Eren. Just go."

When Levi does not say anything, Eren leaves, bowing once to Levi and once to Petra, scampering down the rocks to return to the Air Temple below. She waits until his footsteps have faded to round on Levi.

"You need to be kinder to him."

"This isn't a matter of being kind or not, Petra," he snaps. "Sozin's Comet is approaching and he's nowhere near ready to face the Fire Lord."

"So overworking him isn't going to do a thing!"

Levi stuffs his scroll into his pocket, crosses his arms and leans against the cliff wall behind him. "I never interfere with your lessons; you shouldn't interfere with mine."

"I couldn't stand around watching this for the fifth day in a row and not say anything—you've been working him since dawn and it's nearly noon already. Can't you see he's trying his best but he's too tired to do any better?"

"I was never given breaks as a child and that worked out fine for me."

"Yeah, yeah, Mr. Firebending Prodigy," Petra says with a wave of her hand, and she thinks she sees a grudging look of amusement from him. "But everyone's different, and everyone learns differently. He's just a kid, Levi—he's twelve and he's already got the weight of the world on his shoulders. As his teachers we're supposed to help him with it, not burden him further."

His gaze is hard, his eyes cold as he looks at her, and for one moment she thinks he won't understand, won't listen to her—but then he sighs and slumps down, rests his elbows across his knees and props his chin on his hands. "I don't fucking know how to teach the brat," he mutters.

Petra settles herself onto the ground beside him, pulls him down to sit next to her and links an arm through his. "I didn't know how to teach when I first started either," she says. "But I knew it was very important, and I just tried hard and did what I thought was right."

"That's pretty much what I'm doing."

"Yeah, but you know your opinions of things are kinda skewed sometimes." She gives his shoulder a playful squeeze and he mock-glares at her, but he won't deny that she is right; all those months spent trying to capture the Avatar are a testament to that fact.

"Eren's a smart boy, he works hard, he does his best and yeah, he's the Avatar, but you have to remember he's also just a twelve-year-old kid and everyone expects him to save the world. You explain things well, you're a good teacher, but when he doesn't get something right try to figure out where the problem is and work him through it rather than making him do it over and over again until he does it correctly."

Levi nods slowly and she releases her grip on him to stand; she pretends not to see the faint disappointment she can now easily read in his features, the way his eyes linger on the curl of her fingers where they touched his body. They're in the middle of a war right now and there is no time for anything else, but maybe in the future, after Eren has defeated the Fire Lord and the world is at peace for the first time in a hundred years—maybe then she can let her eyes linger too.

"I'm going to find Eren," she says. "You can resume firebending lessons after lunch; I'll prepare something within an hour."

She leaves him standing there below the cliff, staring at his scroll once more, rolling little sparks of fire in his palms, and she isn't sure if she's just imagining the strokes of her name at his fingertips.

Eren is practicing his waterbending when she reaches the Air Temple, perched on the edge of the fountain and sending swirls of liquid through the air. He drops his hands and the water splashes to the ground when he sees her.

"How are you, Eren?"

"I'm fine," he sighs; she sits next to him and pats him on the knee.

"I'll make lunch soon; afterwards you can practice more firebending."

He winces a little and she smiles wryly. "Having trouble?"

"I always thought I'd have the most trouble with airbending or waterbending," he admits. "With air you're supposed to be weightless, with water you should be fluid… I'm not either. I always thought firebending would be easy because I'm… often angry."

Petra chuckles at that and Eren blushes a little, ducking his head.

"But ever since we came back from meeting the dragons… it's like I've been seeing fire wrong my whole life, and… I dunno, it's different and it's good but I get tired and…" He trails off, rubbing the back of his neck.

"You know he works you really hard because he wants you to succeed, right?" Petra says. "He grew up believing totally different things from the rest of the world and that's how he was taught, but he wants you to be your best and that's why he acts like that."

"I know," Eren says, avoiding her eyes. "I just feel like I can't do it sometimes."

She puts her hands on his shoulders, turns him to face her and makes sure he is staring straight at her when she says, "Eren."

"Yeah?"

"Believe in yourself—remember, we all believe in you. Trust us, Eren."

"… Okay," he says, somewhat reluctantly, but she tweaks his nose and he grins shyly at her.

"Now come on, I'm going to prepare some lunch. Tomorrow I'm stealing you from Levi and if you do well I'll make you something cool."

"For lunch…?"

"No, with bending! What I did, inventing a new form of bending… it was pretty metal of me, wouldn't you say?" She winks at him.

He groans, shakes his head at her with something like embarrassment, and Petra acknowledges that there are some things he shouldn't learn from his teachers.