AN: The Chinese characters in the Avatar universe context are all derived from . , excluding 天下太平. Yes, I am Chinese educated. The full constructed poem is in my profile page, with translations!!
Going through the immense numbers of wedding gifts, given to them by their friends and family, countless allies, well-wishers and supporters, Zuko would have thought that he and Katara would have a full year before they could finish writing all the thank-you notes. Among them, were two twelve-by-twelve feet long calligraphy pieces, hand-written by Master Piandao using a huge brush, with the application and adaptation of Fire-Bending techniques and a mixture of vermillion and ink, red and black, the colors of the Fire Nation. There were four characters in each of the pieces, one stating: 水善火烈, and on the other, it was 天下太平. These eight words meant the world to the young souls who had aided the Avatar in his quest to restore balance to the world, they who had crossed the boundaries of war, hatred and death to find happiness in one another, their union smiled upon by all who loved them, and all they loved. These strips of silk, they were hung in the royal suite of the Fire Lord and the Fire Lady, framed in gold and silver, to forever remain in their sight, hearts and memories.
水善, it had meant the Element of Water, for it was Benevolent, forgiving and ever-changing. And just like Water, she flowed long, powerful and stubborn, for no river had ever changed its course. From the moment she had decided to help the Avatar in his quest to save the world, she had remained true to her cause without even the thought of faltering in her way. Using her powers of Water-Bending, she had defended and healed those who needed her most, carving her own name into the annals of history as the girl who gave hope to those who had none; and now, she would once again carve her own name, as the woman who would aid her husband in restoring order and balance back to the Fire Nation with her husband, and that of the world.
火烈, it was Fire. Fire was ferocious; fire was Strong, passionate and courageous. This was Zuko, son of the House of Agni. Honor-bound and pure-hearted, this soul was never one that was able to give in to mindless, senseless rage and hatred easily (only his forebears and deranged sister were capable of that). As Iroh had put it, he was an idealist, constantly chasing everything he had believed in. For a certain part of his life, he had chased after the Avatar in hopes of restoring his honor in his father's eyes, and then, he had given it all in the name of redemption and his responsibility as a son of Agni to ensure the re-entry of balance in his own Nation and his world.
In truth, 水善火烈 did not mean only Zuko and Katara as individuals. It was also an allegory of their love. Water and Fire were opposites, very much like them, as well as Benevolence and Strength. Yet, when the hand of Fate had given the decree, they were one of the same; two halves of a whole that needed to be completed. Although both of them were completely stubborn, he had needed her benevolence to aid in his redemption, while she had required his passion to find her own. Theirs was a spark that could not be erased, for none could say when one might overpower the other, nor could any deny that each of them brought total balance to the other. It had led to the birth of their love, and the healing of their own individual wounds, brought on by the War that had lasted a full century…
Of course, there was 天下太平, meaning "Peace in all below heaven". This was the goal shared not only by Zuko, Katara and the Avatar. It was the goal of all who lived and breathed in their world. When there was peace, there could be progress, there would be wealth for even the meanest peasants, and there certainly be Balance. Piandao had given these four characters to the Fire Lord and the Fire Lady to remind them of this very important notion that the world must be kept in balance in order to prosper, hoping that in their newfound political influences, they would be able to hold true to what they had fought for that led to the ending of the War. In their later years, it would lead them to the sheer understanding of the need for peace, not only to erase the suffering of all around them, but as a service to Nature, and the Universe itself, for they had known the terrible effects of imbalance, of pain and tyranny. It would all end when天下太平 could be achieved, they were sure of it.
"水善火烈, 天下太平" Zuko recited after the servants in the royal Fire Nation Palace had put the calligraphy pieces up in their chambers, with his wife near him, also admiring the hidden meanings of these eight characters, and the superior craftsmanship that Piandao had in his many years of practice and application. "I'd never thought that they would carry so much meaning to me." He was born to a country that prided itself with war, one in which her Benders drew on anger and rage to power their souls and minds. He would change all of that, he was sure of it. He was sure to achieve his goals. That was why he had changed the characters of his name from "祖寇", the Ancestral Usurper, to "苏科", the Resurrected Rule, despite the fact they sounded the same in the dialects of the Fire Nation. He would renew the face of the Fire Nation, and redeem her, just as he had redeemed his own honor and his own soul, he was sure of it.
Katara smiled at her husband, and did not utter a word. Zuko was always the brooding, angst-ridden warrior, and even after two years of peace (and three days of marriage); there was no clear indication of him existing in any other way. Placing her head on his broad shoulder, she exhaled a sigh and closed her eyes, turning the sounds of the chirping birds, his steady breathing and heartbeat into a lullaby of her own, and slept in his arms, tired after a long day of attending to court matters, sparring with her Fire-Bending husband, and the various official functions they had to attend.
It did not take Zuko long to notice that Katara had fallen asleep, following which he dutifully transported her to her place on the bed of silken sheets the color of the purple dawn, yet another culmination of their love and heritages. He kissed her on the forehead and wished her good-night before focusing his attention of the calligraphy pieces again. He knew that whatever the cost or the challenge, he and Katara would ensure Peace flowed to every corner under Heaven. He was sure of it.