This story is told from Ozai's POV and is meant to take place after the series ends while not necessarily following the events of The Promise comics. I don't own Avatar: The Last Airbender or any of the characters therein.
Chapter 1: Zuko
Five hundred thirty seven days. I am imprisoned still. After a mockery of a trial at the behest of my Pretender son, I have been sentenced to rot here until "such a time as the Avatar deems me fit to release". Nonsense! Since when does the Avatar determine the fate of the Fire Nation? My grandfather Sozin was far too soft where the Avatar's previous incarnation, Roku, was concerned. He did not yet understand the importance of sacrifice in his quest for greater power. As a consequence, he proved unable to use the providence of Roku's proximity to him to aid in his quest. Instead he proved to be nothing but a distraction- delaying Sozin's plans by decades. However, rumor has it that he eventually saw the light and allowed Roku to die twelve years before the arrival of what is now known as Sozin's Comet. Thus he ensured that not even the Avatar would stand between him and his victory. My son, weak from the day he was born and further corrupted by my brother's teachings, has doomed himself to repeat Sozin's mistake. He has substituted the Avatar's judgment for his own and in doing so diminished the power and glory of himself and the rest of the Fire Nation. But he will see. I will make him see. And he will at learn to fear me once more.
***********After the Comet***********
Consciousness comes back to me. The bed feels unusually stiff beneath my back. I open my eyes not to see the ceiling of my bedchambers, but the top of a prison cell. Memory of the past few days returns in a flood of defeat, shame and anger. Something else as well. Weakness? No. Never weakness.
What woke me? Footsteps? Yes. I hear them approaching, then halting just outside in the hallway. A large metal door with a single barred window swings open, revealing that traitorous boy Zuko in the Firelord's robes. This is too much.
"I should count myself lucky. The new Firelord has graced me with his presence in my lowly prison cell."
"You should count yourself lucky that the Avatar spared your life. Banishing me was the best thing you could have done for my life. Maybe your time in here can do the same for you." I see the willful little wretch who taunted me on the day of the eclipse is here to stay. He has not learned well enough to fear me. Or has he? Does he intend to finish me off while I sit defenseless in my cell? Bribe the guards outside for their silence? Surely he knows that true patriots of the Fire Nation will not stand for his incompetent rule for long. As long as I am alive his position as Firelord is far from secure.
"Why are you really here?" Zuko narrows his eyes in what I assume is anger, though I know he must enjoy looking down on me as the one who stole the flaming throne.
"Because you're going to tell me something. Where is my mother?" I don't bother concealing the smirk that comes to my face at his plea. This may be just what I need.
"Not even a week as Firelord and you're already crying for your mommy. My, my, how far my bloodline has fallen." He shoots a fireball into the cell so that it impacts the ground less than two feet away from where I sit.
"Do you think this is a joke?!"
"Yes. Like everything you have ever done, all this amounts to is a joke. Not even a very good one." Zuko draws himself up, trying to convey a sense of superiority that we both know he is not entitled to.
"That's big talk coming from a deposed Firelord who can't even bend anymore!"
"At least when I could and tired to teach you a lesson with firebending my aim was better." Shock resounds on his face, still half-scarred from that failed lesson. Then his expression turns into an enraged snarl as he turns around and storms out of the room, slamming the cell door behind him. I have won this battle. And his reliance on me ensures that I will live to win the war.