David Weber

“Tisiphone stood silent and helpless in Alicia's mind. It was all she could do to keep Alicia's blind savagery from dragging Megaira under and clouding the lightning-fast reflexes which kept them both alive.
She'd never guessed what she was creating, never imagined the monster she'd spawned. She'd seen the power of Alicia DeVries's mind without recognizing the controls which kept that power in check, and only now had she begun to understand fully what she had done.
She had shattered those controls. The compassion and mercy she'd feared no longer existed, only the red, ravening hunger. Yet terrible as that might be, there was worse. She'd found the hole Alicia had gnawed through the wall about her inner rage, and she couldn't close it. Somehow, without even realizing it was possible, Alicia had reached beyond herself. She'd followed Tisiphone's connection to the Fury's own rage, her own destruction, and made that incalculable power hers as well.
For the first time in millennia, Tisiphone faced another as powerful as herself, a mortal mind which had stolen the power of the Furies themselves, and that power had driven it mad.”
― David Weber, In Fury Born