Trigger Warning: This is animal cruelty so yeah avoid it if you're not into that.
Fire ran through her veins as Koyuki walked into an open field. The stars above shone like tiny diamonds dotting a black fabric. Unfortunately, what she had in mind wasn't stargazing. Her robe grazed the soil as she walked silently, further, and further away from the Senju encampment.
Her feet stopped in the middle of the field. She silently looked around, checking for any soul that might be wandering around at this time of night. No one was to be seen as far as she could see at night. A telepathic scan proved that no one could be found within the next kilometre. Perfect.
Koyuki set down the wooden tub from her left arm and the steel cage in the vice-like grip of her right hand. Channelling chakra into her right hand, a large glass tub appeared before her. The next step was to fill the tub with sulphuric acid. Lighting a lantern, she held it in front of the glass tub to see it half-filled with a clear viscous liquid.
Ignoring the faint squeaking from the steel cage, Koyuki lifted the wooden tub and held it closer to the sulphuric acid. As she removed the lid, hundreds of cockroaches poured out from the tub and into the sulphuric acid. The acid hissed and steamed, slowly dissolving the cockroaches as they squirmed however much they could before all that was left were corroded insect scraps. It was pure sulphuric acid after all. The cockroaches were dead, time for the rats to join them.
Koyuki made four duplicates of the lantern, placing them at the four corners of the steel cage. The light shone on the snouts of the vermin. Of course, they were scared, her eyes were icy cold, and her chakra was leaking killing intent.
Koyuki raised an eyebrow at their quivering forms, nonchalantly stating, "Well, I'm sorry for what I'm about to do. You're vermin and a threat to the health of everyone in the camp. Besides, it's better if I do what I'm going to do to you, instead of the people I want to direct my anger at. If I don't do this, I won't be able to overcome my hatred at all. So, farewell in advance."
An iron cauldron and a large bottle of bleach appeared in a puff of smoke.
"Suiton, suiryudan no jutsu."
Four water dragons, each the size of her arm flew into the cauldron, filling it to the brim with water.
"Fyreay"
Dark purple flames lit up at the base of the cauldron as the water slowly bubbled. As long as she willed it, the flames would help heat the water, nothing more. The dark flames crackled and roared as she sat in front of the cauldron. The steam would take away her wretched hatred, which reared its head every time she saw her brethren.
Kou Uzumaki had blonde hair that shone like the golden rays of the sun and a dazzling smile to match. Koyuki Uzumaki now stared at the steam, passing on her most painful memories to the cauldron.
The times they beat her. Every bad word, every curse they had called her. Every time they stared at her in disgust. Every time she read minds, only to find thoughts of hatred and none of love or at least indifference. The time she had cried on the beach, killing everything within a thirteen-meter radius. What did she say back then?
Oh right. Now she remembered.
What did I do wrong? I had never wanted to kill my mother. I didn't even know I did it. Had I known that being born would kill her, I wouldn't have wanted this life. I want her here with me. I'm sorry, ok? I'm so sorry, please forgive me. I'm sorry I can't do better. I'm sorry I can't reach your expectations. Please, please don't hate me. I'm sorry. Why do you hate me so much? Am I really that unredeemable? I hate you. I hate you all so much! All of you, die! Just go and die, ok? I never want to see you alive!
That day, the fish in the sea and the trees around the beach all seemed to follow her unintentional command. Around a hundred fish went belly up, washing up on the shore and the trees withered away, leaving their ashes to be carried away by the wind. That event had left her with a very sore throat and her grandfather making plans to send her away. Someone saw that disgraceful act.
As she snapped back to reality, the water was done boiling. A ladle was summoned. Ladle by ladle, the hot water was scooped up and poured on the rats. They squealed. Why wouldn't they? The water was hot enough to burn their fur off. Rat fur lined the floor of the cage. The rats had bald patches which were swelling red with blisters. Chuckling, she taunted, "This, and you guys start squealing? The worst has yet to come, little ones. Go ahead, scream all you want. No one will hear you and no one will save you."
When the hot water had been depleted, Koyuki unscrewed the cap off the bottle of bleach, making extra care to pour it on the areas where the rats had been scalded. The rats screamed and cried even more. Even so, her expression remained icy cold as the bottle was emptied.
In the place of the rats and the cockroaches, she envisioned the visage of everyone who had hurt her. Did it solve her problems? Not really. Catching the pests was quite the hassle and the clan elders were still alive and well. Did it get rid of her hatred? Some of it was still there but she had her revenge, in her own way. She now wanted nothing to do with them, now that she had revenge, albeit on their "replacements." For them, she now felt neither hatred nor love. It was all just bitterness and indifference.
Heaving a large sigh, she bathed all her equipment in dark purple flames as they disintegrated into ash, leaving nothing but indents in the grass where they had once been. Koyuki walked back to the tent to sleep, her gaze empty and her heart a little lighter.