I do not own any ATLA characters or storylines, or the concepts and world building done by Philip Pullman. All daemon character names and characterisation are my own. Title of story, chapters, and quotes are taken from the lyrics of 'Birds' by Imagine Dragons, I do not own that either.

Everything you need to know about His Dark Materials to keep up with this story:

1. everyone is born with a daemon, which is like the physical manifestation of a soul as an animal form outside the body

2. children's daemons can shape-shift into different animals. As they reach puberty in their teenager years, it "settles" into a fixed form which reflect their personality or character

3. the daemons are capable of speech and independent thought, and have their own names. (see end notes for the meanings behind naming of daemons in this story!) They are usually of the opposite gender as their human, though exception exists, it is extremely rare.

4. daemons can touch and interact with each other and their own humans. Touching another person's daemon without consent is a huge violation and can cause distress and discomfort to both the daemon and their human. Touching another person's daemon with consent is an extremely intimate thing to do.

5. most people's daemon cannot be too far away from their human without causing distress and discomfort. However they can be trained to be able to extend the range. Permanent and forceful severing of the bond kills both human and daemon.

Two hearts, one valve,
Pumping the blood, we were the flood
We were the body.
Two lives, one life,
Sticking it out, letting you down,
Making it right.

Even before she settled, Hikari's form has always been a source of conflict between Zuko and his daemon for as long as he could remember. Azula's daemon has never given her any problems. Ihnatzius had been a kitten when she was born, and rarely changed from the dark tabby cat with the piercing, calculated gaze in her youth. As she grew out of her toddler years and took to firebending with ease, her daemon, too, began experimenting on his own, shifting into a lynx or caracal or an ocelot on the side of the training court, gazing at his human as she mastered kata after kata, leaving her older brother behind in the dust.

Ursa told Zuko that his own Hikari had been a little duckling in the first few days of his premature birth, perched on the edge of the pillow as Zuko's tiny chest drew breath after breath, or settling down on the head of Ursa's cheetah for warmth as she cradled her son and prayed to Agni to fuel his life force.

She did not tell him how Ozai peered down at the bird, pursed his lips and sneered at her black beak and grey hatchling feathers, and declared that no firebender would have that…creature as their daemon, and ordered his own son to be disposed of. Ursa protested violently and the fire sages explained how there were no evidence that a daemon's form at birth is in any way linked to their human's aptitude or success in later life, but it wasn't until two weeks in, when finally Zuko's breath no longer hitched and stopped at random intervals, and Hikari shifted for the first time, that Ozai had looked down upon the explosion of black spots across her soft golden fur and nodded in approval.

She told him, instead, of how his daemon had shifted the earliest in the generations of Fire Nation royalty of whom records existed, and how his first shift had been a mighty and strong jaguar cub. In the years that came, every time Azula bested him in training, or Ihnatzius had Hikari's bright feathered chest pinned to the ground, Zuko held this knowledge to his heart. This was a pride Azula can never take from him.

As much as Zuko tried to keep his daemon in a form appropriate to a Fire Nation prince as he grew up, and despite her early head-start Hikari had always had immense trouble being a large cat. They compromised in that whenever they were in Ozai's presence, Hikari would carefully shift into a leopard to match his father's. In private, she was left to be what her heart desired that day. Despite their greatest combined effort, however, they would often find that a raised voice from Ozai, or a sudden prance of his Thera would send Hikari leaping into the air and shifting into just about any bird possible in a burst of feathers, much to Ozai's disdain and Zuko's mortification.

"It's not my fault," Hikari would later chirp with the defiant tone she only dared use on her own human, settling as a bright green woodpecker on the windowsill he was leaning his back against, "You're the one who's always on edge around him, it makes me flighty."

"Maybe if you gave me enough reason to trust you not to embarrass us, I wouldn't be so on edge!" Zuko shot back hotly, the humour of Hikari's wordplay lost completely on him.

"Perhaps next time if we tried a cat form like Ihnatzius I would have less trouble holding it." Knowing the wound of that morning's most recent embarrassment was still burnt fresh in Zuko's mind and that arguing now was pointless, she offered instead.

"No." Came the adamant reply, "Azula may be content being a subordinate to father, I need to show him I can be as good as him, and uphold his name in honour." Zuko decided with as much adamance in his voice as a nine year old could manage. Turning to address his daemon, he steeled his face and matched his voice to the way he heard his father talk to palace servants, "you will be a leopard the next time I'm summoned before him, and you will hold the form for as long as we are in his presence."

He stood up as if to leave, then turned around once again.

"Are you coming? And change out of that ridiculous form! What if someone sees you like this?"

Sighing, Hikari took flight into the air and shifted into a small rusty-spotted cat upon landing at her human's heels, and followed him out of the door.

"What do you want, Ihnatzius?" Zuko asked irritably as his sister's daemon, a dark brown tabby again today, approached him and Hikari by the pond.

Azula was nowhere to be seen. Over the past couple months she had become increasingly obsessed with training herself to be more separated from her daemon. Often times in the morning when the sun has barely risen, Zuko would find his sister sat cross legged in the courtyard meditating - eyes closed and biting into her own lips, no doubt trying to drown out the sensation of pulling, as Ihnatzius stood a few metres away, tails stiff, fighting every step away from her.

Once, after he'd caught her practising for the first time and demanded to know what she was doing, Zuko had coaxed Hikari into giving it a shot in the privacy of their own bedroom, both out of curiosity and not wanting to be overshadowed by Azula in yet another field. The pain had been like nothing else. It felt like iron nails scratching against his ribcage and someone twisting his lungs and his heart being pulled out of his oesophagus and he can hear his blood roaring in his ears and thump thump thumping to the rhythm of his daemon's tiny wings as the scarlet hummingbird fluttered desperately on the other side of the room.

It was Zuko who gave up first, running toward Hikari and plucking her out of the air. They flopped down into the bed together as he stroked her feathers and beak and babbled as tears streamed down his face (when had he started crying?) that they'll never, never be apart again. He doesn't think he'll ever go through anything as awful as this. (He will look back on thinking this and chuckle drily at how wrong he was, while running a finger across his scarred face, but that would come later.)

He wondered how on earth Azula does it.

Ursa had been furious when she found out. Pacing back and forth in Azula's bedroom as the young girl sat indignant on her four poster, throwing her arms up in the air and ranting about how dangerous and reckless it was, the risk of permanent damage and possible death, and tales of children and adults alike, severed from their daemons permanently, eyes glassy and unresponsive, body giving out a few days later. Azula stroked her tabby's fur idly, shrugged and pointed out that most Fire Nation generals and nobles have trained to be able to do this, to varying levels of success.

"As adults, Azula!" It was Takeo who spoke up this time, surprising the other three in the room. Though addressing the girl directly, their mother's cheetah was staring sternly at Ihnatzius. "Or late teenagers if they're pushing it, not as eight year old children who knows no control or boundaries! Spirits, what were you thinking?"

When he'd heard about this, Ozai merely informed his daughter that he would be disappointed should she make an irreparable mistake that would bring shame upon the family, with the faint hint of an approving smirk upon his face. Azula took this as permission enough to continue her training, and before long, it wasn't a rare sight to spot a large striped cat running across the grounds without a human to be seen, almost as if it were a stray.

"Azula invites you guys to come play." Ihnatzius purred, the hint of youthful mirth that has long vanished from his human's voice still present in his. "Firebending wrestle."

"We're not allowed to firebend without masters present, she knows this." Hikari spoke up softly from Zuko's lap.

"Pfft, suit yourselves, pickens."

"We're not pickens!" Zuko yelped indignantly, bolting upright and causing the white cat that is Hikari to tumble from his lap. "We're playing." He declared, marching to follow the tabby and pointedly ignoring his own daemon's attempt to tug him back indoors.

Azula stood waiting for them in the courtyard. Her face lit up in a grin that wasn't fully sincere, but enough so that Zuko couldn't quite put a finger on what's so unsettling about it either.

"Hello, Zuzu." She greeted.

"Heard you wanted to wrestle," Zuko offered, taking his stance already, "Let's."

Azula shrugged, still grinning, and took her place.

Though Azula had mastered more forms than he did, fancier punches took more concentration and time out of her to deliver perfectly. Zuko, not striving for showmanship, sticking to the basic katas and keeping on his feet, found himself not completely at a disadvantage against his sister's advanced ones just yet. Lately however, he noticed her flames getting hotter and were being conjured faster, and himself beginning to lose matches more often than he won.

Today, however, Agni seemed to shine in his favour. Twenty or so minutes in, Azula's defence started to drop and opened up opportunities. In a couple rapid successions of punches, Zuko had her pinned to a railing at the edge of the courtyard with a flaming fist raised over her head. He smiled, not maliciously but nevertheless pleased with himself for not being bested by her this time, and was about to quip a joke or two when he felt his throat start to burn.

Reeling around instinctively, the two children saw a flurry of fur and claws in the centre of the courtyard. Hikari, in the commotion and distress had turned into a red squirrel, and was currently being pinned to the ground by Azula's daemon, squeaking furiously. Ihnatzius was taking the form of an adolescent lynx, whose single paw covered the entirety of Hikari's torso as he put increasing amount of pressure on the poor squirrel's chest. Zuko fell to his knees and started wheezing, eyes widening in horror as his daemon's chirps became less angry and more desperate, and he's not sure wether or not he was imagining the laughter that came from behind him where his sister stood as his vision dimmed.

A blur of gold sent Hikari scrambling from under the large cat and scurrying into Zuko's arms once again, bushy tails ruffled and still trembling. On the other side of the courtyard, the lynx dangled awkwardly by the scruff of his neck from the jaws of a cheetah, the former's adolescent size and struggling made it difficult for the latter to maintain control.

"Azula!" Ursa gasped in sync with Ihnatzius's loud whine.

"Let me go, Takeo!"

With a nod from his human, Takeo dropped the other daemon rudely to the ground. The lynx ran towards his human, with a graceful leap, transforming midair, and settled into her arms in its usual tabby appearance once more.

"I thought we talked about not hurting people, daemon or not, Azula. What do you think you're doing, young lady?"

"We were just playing, mother." Azula quipped sweetly, the chilling innocence she put into her voice making Zuko shiver. "Iggy didn't mean it, did you Iggy?"

In her arms, Ihnatzius licked away at his paws, pointedly ignoring the conversation altogether. Ursa sighed, about to turn away, when Takeo lurched forward abruptly, stopping just short of Azula and let out a low and vicious growl, pulling his lips back to bare his fangs at the young girl.

Zuko had never seen his mother's daemon so furious before. He felt his sister's breath hitch beside him and his own heart starting to pound, despite not being targeted by Takeo. Few things have ever shaken his sister to this depth, but the poor girl's eyes were wide as she clutched Ihnatzius to her chest, peering down at the animal just coming up to her shoulders. In that moment, Zuko thought, Azula resembled her age of eight years for perhaps the first time in a long while.

"Takeo!" Ursa exclaimed, no less shocked by her own daemon's acting out. The spotted cat snapped out of its aggression immediately, and stalked over to his human, still glaring at Azula. Ursa turned to her daughter, "you and I need to talk tonight." She said tiredly, taking her leave.

A/N Behind the Names:

Zuko's daemon Hikari (hee-ka-ree) is of Japanese origin, meaning "light" or "brightness"

Azula's daemon Ihnatzius (ee-na-ccius) is of my own creation, from the variation "Ihnat" derived from the name "Ignatius" (hence his nickname "Iggy"), which means "flame" or "fiery one' in latin.

Ursa's daemon is an Asiatic cheetah, Takeo (ta-kee-o) is a name in Japanese meaning "strength as military"

Ozai's daemon is a Persian leopard, Thera means "wild" or "untamed" in greek.