Iroh once said to use lightning a firebender needed to be focused and not driven by raw emotion. I think this means they need to be at harmony, or at peace with themselves, or completely and coldly dispassionate. I wanted to illustrate what I believe Zuko might have been thinking at the moment he achieved his epiphany.
It all happened too fast. The great circle of father's arms, trailing lightning and bringing the trailing chains of electricity together in less than a second. Time was up, I had tarried to long…oh, far too long…United by a common purpose the screeching chains of light reached out for me, the eerie greenish light casting the room into a hellish scene that promised death.
My brother is not an understanding person…The soft, contemplative voice of my uncle, making an observation I knew was true but refused to listen to. I wanted my father to love me again, and I could only see one way that could happen. If your father really wanted you back he would have let you return…Avatar or no Avatar…The haughty, mocking voice of Zhao, telling me something I should have seen a long time ago.
Two fingertips caught the lightning, and I felt it wrap around me in a savage embrace, pushing me back with a physical force as father pushed it towards me, willing it to tear through my body, snuff out my life. But the technique used against me was brute force, the cold fire filling the air with ozone and failing to strike me as I funneled it into my arm, down…
Is your own destiny? Or is it a destiny someone else has tried to force on you? I'm begging you, Prince Zuko! Its time for you to look inward, and start asking yourself the big questions! Who are you? And what do you want? Uncle was right. I wanted to go home, but I paid far too high a price to do it. You are free to choose. Azula's cold voice, reminding me of what I did. I chose wrong in Ba Sing Se. But now, I can do the right thing.
Down, down, the furious shaking power of the lightning still pushing me back across the floor, feet sliding and trying to find purchase on the smooth surface. I learnt this technique from observing the waterbenders…The burning, teeth-shaking power of it filling my arm to the brim, funneling down, further down…you must not let the lightning pass through your heart…
It already has, Uncle. It did that second fire burnt my face. My stance locks, my backward slide stopping as I draw in my arm. Down into your stomach…The power of the lightning poured down, my chi rippling in response, flowing down from where it still funneled into those two outstretched fingers, even though I now held them close to my chest. I'm tired.
The touch of a hand on my shoulder, warm and comforting in the cool air. The memory of long ago, the touch of a father's hand heavy as he stands beside me. So long ago…I'm tired of running away. "Then rest…a man needs his rest." No more running. Just one more thing to do. I push out my other arm, lightning sprouting from the fingertips and hungrily reaching for my father. The lightning is mine now.