This is a dark story.

  So once upon a time, there was an Absol named Coal. She was a normal absol, living a normal life. One day, a trainer caught Coal. He was a mean trainer, only using Coal to try and avoid danger for him. He abused all of his pokemon. For Coal it was smothering her usually bright coat with charcoal, and removing her gem-thing in her forehead. One day, as he was giving Coal a beating, his charmander came out. Coal was nearly dead from this beating, she was crying and begging for mercy, but the trainer kept beating her. The charmander, named Char, was Coal's best friend. He saw her being killed and tried to stop the trainer, but the trainer simply killed the charmander instead, and forced Coal back into her pokeball.
That night, Coal had a dream from Arceus, He was angry at the trainer, and knew that the sould of Char was restless, so gave Coal the power of a charmander. He healed her wounds and gave her a new gem-thing. All of her toes were changed to coal, as well as her tail and her head-slicey-thingie and gem-thing. In the morning, she was set free. Everything that had been changed to coal the night before was now flaming. Coal herself felt a flame ignite within her and knew what she had to do. The absol went back and killed her trainer, revenge for everything he had done. And that is the story of the fire-type absol, and why she hates everyone.