Unforgivable Secrets [ZukoXOC]

She is an assassin trained by a fire nation general. He is a prince without a kingdom.
She has to hide her true power to keep her life. He has to hide his to keep his freedom.
She is the villain. He is the hero.
She is water, cruel and unforgiving. He is fire, raging and dangerous.
She didn't agree to that arrangement. He didn't particularly care.
She has her secrets. He has his. And, sometimes, those secrets are unforgivable.
***
Kaida Shao had met prince Zuko once upon a time, right before he was banished by his father. Then, she had left to train with one of the Fire Nation's deadliest generals.
For years she had been part of the best team of assassins in the Four Nations, the only place where it was safe for her to use her unique set of gifts.
Zuko made a promise once, and he intends to keep it. Should he ever meet the blue-eyed dancer again, he will not let her get away from him that easily again.
After he becomes Firelord, he is dead set on keeping that promise, even if it might put more than just his life in jeopardy.
And Fate has a strange way of moving around in circles, making their paths cross once again.

ZukoxOC