No turning back.

Ursa walked down the hall, her body humming with an unfamiliar power. She could feel it, the muscle memory of Azula's hard work, the skills and techniques that her daughter had honed over years of relentless training. It was a strange sensation, like wearing someone else's clothes, someone else's life. She marveled at the strength that coursed through her veins, the power that crackled at her fingertips. She had never felt so strong, so capable. And yet, the feeling was bittersweet, tainted by the knowledge that this power was not hers, that it had been stolen, taken from a child, her own daughter.

The palace servants saw her coming and fearfully pressed themselves against the walls, their eyes wide with terror and awe. They had heard the rumors, the whispers of the Agni Kai, of Ursa's challenge to Ozai. And now, they saw the power that radiated from her, the cold fury that burned in her eyes. They knew better than to stand in her way.

Ursa noted their reactions, and a dark, twisted thought bubbled up from the depths of her mind. Pathetic bystanders, she thought, her lips curling into a sneer. They stand by and watch as the world burns, too afraid to lift a finger to stop it. They are no better than the rats that infest the palace walls.

The thought shocked her, its venom and malice foreign and disturbing. But even as she recoiled from it, another followed, and another, each darker and more twisted than the last. She could feel Vaatu's influence, his negative energy seeping into her thoughts, corrupting her mind. And she found that she did not entirely hate it. It was empowering, in a way, to feel such strength, such rage. It was intoxicating, addictive.

For once she was the one in control, not them...

...But she knew she couldn't keep it forever, Just until the Agni kai ends, she tells herself, ignoring the chuckles echoing in her head.

She reached the training room, her heart pounding with anticipation and dread. But before she could step inside, she heard a familiar voice, a familiar cry.

"Mother!"

She turned to see Zuko running towards her, his eyes filled with tears, his face streaked with dirt and grime. He looked like he hadn't slept in days, like he had been wandering the palace halls, lost and alone.

Ursa's heart ached at the sight of him, and she opened her arms, enfolding him in a tight embrace. "Zuko, my dear," she murmured, stroking his hair gently. "What's wrong? Why are you crying?"

Zuko clung to her, his body shaking with sobs. "Mother, please," he begged. "Please don't do this. Please don't fight Father. He'll hurt you, he'll kill you. Please, just beg for his forgiveness. Please, Mother."

Ursa's heart broke at the desperation in her son's voice, at the fear that gripped him. She wanted to comfort him, to ease his fears, but she knew that she could not. She had to do this, for him, for Azula, for herself.

"Zuko, my dear," she said, her voice gentle but firm. "I have to do this. I have to stand up to your father, to show him that he cannot treat us like this, that he cannot throw our lives away like they mean nothing."

Zuko looked up at her, his eyes wide and pleading. "But Mother, he'll kill you. He'll kill me. He made a deal with Grandfather, he promised to... to..." He choked on the words, his eyes filling with fresh tears.

Ursa's heart pounded in her chest, her mind racing. She had to make him understand, had to make him see that she was doing this for him, for his future. But before she could speak, Zuko pulled away from her, his eyes filled with a newfound determination.

"I'll go to Grandfather," he said, his voice shaking but resolute. "I'll beg him to stop this, to make Father see reason. I won't let him hurt you, Mother. I won't let him hurt us."

Ursa's heart swelled with pride and love, but also with fear. She knew that Azulon would not listen, that Ozai would not be swayed. She knew that this was a fight that she had to face, a battle that she had to win.

All of Zuko's efforts will just end up with him getting hurt. She doesn't have time to be worrying about him right now.

"Zuko, no," she cried, reaching out to stop him. But he was already running, already fleeing down the hall, his footsteps echoing through the palace.

Frustration welled up within her, hot and bitter. She called out to him, her voice echoing through the halls, but he did not listen, did not turn back. And as she watched his retreating back, she felt a surge of dark energy, a wave of malice and rage that threatened to consume her.

Vaatu's voice echoed in her mind, his words like poison, like fire. "Stop him," he hissed. "Make him see, make him understand. Show him your power, show him your strength."

And so, she snapped.

"Zuko, I said STOP!" she roared, her voice echoing through the halls like thunder. The flames in the room surged outwards, a wave of heat and power that sent Zuko tumbling backwards, his eyes wide with fear and shock.

Ursa stood there, her breath coming in ragged gasps, her eyes wild and burning. She looked down at her son, at the fear that gripped him, and she felt a pang of guilt, of regret. But it was too late, the damage was done.

"Zuko," she whispered, her voice trembling. "I'm sorry, I didn't mean to... I just... I'm just nervous, about the Agni Kai, about everything. I didn't mean to scare you."

Zuko stared up at her, his eyes wide and fearful. He stammered, his words tripping over themselves, his voice shaking with terror. "M-Mother," he whispered. "Y-Your eyes, they're... they're glowing."

And then, before she could say another word, he turned and fled, his footsteps echoing through the halls like the beat of a frightened heart.

Ursa watched him go, her heart heavy with guilt and regret. She had not meant to frighten him, had not meant to lose control. But she had, and now, she had to face the consequences.

She shook her head, pushing the thoughts aside, blaming the nerves, the stress, the pressure. She would apologize later, she told herself. She would make it up to him, she would make him understand. But for now, she had to focus, had to train, had to prepare.

With a deep breath, she turned and stepped into the training room, the door closing behind her with a soft, final click. The room was empty, the air filled with the scent of smoke and ash. She took a deep breath and walked in.

And as she began to train, to hone her newfound skills, she could feel Vaatu's presence, his dark energy, his malevolent power. She could feel it coursing through her veins, burning in her heart, whispering in her mind. And she knew, with a cold, bitter certainty, that there was no turning back. She had made her choice, had chosen her path. And now, she would walk it, whatever the cost, whatever the consequence. For her children, for herself, for the future of the Fire Nation.