Note: The prompt for this chapter is Soulmate AU.

One more chapter to go, folks! Thank you to those have reviewed so far :)

Souls

Aang blinked and he was floating above a scene with a ruined palace courtyard. He saw his own body struggling to keep itself standing up as if in a war with itself, eyes flashing from violet to bleached white. Katara was grasping his body's forearm, eyes closed, face eerily calm.

He blinked again, and he was nowhere near the same scene.

He rose in the middle of a dilapidated structure made of run-down planks that were half-eaten with rot and nailed together with rusty iron. Thick, twisting tree branches snaked through a rectangular open window. Another broke the ceiling and proceeded through the floor, holding up the poorly made building in the treetop it stood in.

There were pieces of wobbling, rickety furniture. A stool with three legs and with uneven lengths, a crate being utilized as a table, a cracked Pai Sho board with missing playing tiles. There were inky shadows in the corners that filled the lines in between the timbers. Outside, it looked impossibly bright. It was oversaturated with odd tones of pigment and motes of speckled dust that lightened the room.

"That was a brave thing that girl did, you know," said someone. Their voice broke the silence.

Aang saw as upon the three-legged stool there materialized a man in unkempt, draping, orange clothing. He was young, maybe just a few years older than Zuko was. He was scrappy, youthful, with a demeanor that told of a boy trying at being older than he really was. He was cleanshaven with dark, black hair that stood up in a mess of spikes.

His eyes were a Fire Nation golden brown and had a piercing quality to them that Aang recognized, but he could not quite figure out from whom. It was determined like Zuko's stare, kind like Iroh's, but there was something ancient and knowing behind them that reminded him of Roku.

"It was brave," the man continued, lips quirking at one end, "but it wasn't ever going to work…trading places like that…not in the way she thought."

Aang felt a pull, a call, from someplace inside himself. He stepped toward the man and left the center of the room. "Who are you? What are you talking about?" he asked. He stopped walking when he was only a few paces away. He was in the patch of light that spilled from the window.

The man chuckled. He leaned forward and placed his chin on his palm, his elbow resting on the crate. "Wan," he introduced himself, "but you already knew that didn't you?"

Aang gasped as soon as he heard the name. There was a click, a resounding bell that tolled and that he thought he could feel resonating within him. An invisible force sliding into place.

For a moment he saw himself as an old man in an era long gone, surrounding by snapped arrows and shattered weapons on a battlefield. He apologized to Raava.

"It's hard, you know," started Wan again and bringing Aang back to reality, "to live nearly ten thousand years and to live so many lifetimes." His gaze lingered on Aang's. "But what doesn't change is that every life is new, and every life is a continuation of the last one."

"You're…the First," Aang whispered, almost in quiet reverence.

Wan stood up from his stool, and it faltered for a few seconds before it stabilized. He met Aang where he was, and they were bathed together in the same beam of sunlight.

"You know what else doesn't change?" Wan spoke again. He smiled albeit with a bittersweetness. "The fact that in every new life we have, we remember what it's like to be human."

He pointed to Aang's chest, and it glowed softly with the same light of Raava's intricate patterns, reacting to his presence.

"In every life we have Raava, the spirit of light and peace with us. But there is a balance that is maintained and still, Vaatu, the spirit of darkness and chaos must exist," said Wan. "They have an eternal battle, you see, like that of our own world's. No matter if they are there or not, the essence of them always remains…because the world is like that. Because humans are like that."

It sounded like an archaic parable told to children as a bedtime story. But Aang knew, as he did the other lives he has had, what was true.

He did not have to be reminded that there was great good and great evil that existed in the world. He lived through a war that proved that. He had longed, beyond all else, for Gyatso to be alive, for his people to come back.

"What Master Katara did was pure and courageous, and so, so human," Wan began again. His expression was unreadable. "That is exactly why it didn't work."

Aang clenched a fist at his side. "What happened to her?" he pressed. "What happened to Katara?"

Wan bowed his head a little, and there was something kind in the way he looked at him. "She returned to her body, as you soon will," he remarked. "She healed your soul, as only a person bonded with the soul of an Avatar could. She helped you to remember that there is love in this world, love that is reborn." He paused, peering at him in an inquisitive fashion. "Vaatu made a gamble that he was sure to lose, even if he didn't know it. For his error, he returned to his jail. He gambled on the fact that he could bond with any human, and for some that might be true. But he forgot that there is something even stronger than peace and chaos, even if they rule our lives, even if they are connected.

"Love is what makes us human, Aang. It's what has driven our incarnations to do what they have done, what we have done. It is the ultimate balance…not good, not evil. It is the reason why a soul is born alongside every reincarnation, a soul to help the world remember that the Avatar is human…because they have forgotten before."

Wan's eyes were bright with white light, and all Aang could see was himself sitting cross-legged in a locked room alone.

The wooden floorboards he sat upon did not even creak as he stood on bare feet. The resounding silence followed him, an infinite specter that clung to his shoulders like a heavy cape. He paced, sliding open the window to witness the morning as it blanketed the bamboo forest outside. He closed it, and then the shadows in the room grew darker. He opened the window again and the moon was full and the stars a hoary bright.

He stared at a copse of trees just below him, for he was so far up. He waited and waited, but no one came.

It was then that he turned to the empty teapot that rested on the chest in the corner of his prison. He called for a servant to fill it with water. His hand went to his sleeve where he had hidden the packet of powder that he had swiped from the apothecary while on a visit to the islands where the people of the element of fire resided.

All he wanted was to be free.

The light subsided, and Aang was looking at Wan again. They were both misty-eyed.

"A spirit is born out of necessity, out of wishes. A soul is often born like that too. And if the wish is strong enough, then they will be reborn again and again," Wan explained. His brow was crinkled, and he could not look at Aang directly for a time. "The people forgot that we are like them...until the fourth Avatar, Kun, and he paid the price for it. It was the powerful, resilient wish of the person that loved him most to give him the humanity he deserved."

Aang let out a breath he did not know he was holding. Rivulets of tears ran down his cheeks.

"I've made many mistakes, but I think this is the biggest one," Wan sighed. He did not look away from Aang again. "I told the people that I was part of legend when I had forgotten to remind them who I really was, and that thought continued from one life to the next."

His firm hand grasped Aang's shoulder as he spoke. "But love has foresight," he said quietly. "You will meet across times, across lifetimes, in different places, in different eras. You could be friends, you could be family, you could be lovers, but you will meet…and when you do, your heart will remember that promise."

When Wan released him, the branches and the timber fell away. He was rushed through a myriad of moving pictures, pushed back through space.

He only halted for a moment in a filed of white. A palm opened before him, and he could not stop the smile that settled upon his face.

"I found you," Katara said, and he was whole.