The Nine-Tailed Sage

The traveler sat, nursing his ale. Seeing nothing of interest in the empty tavern, he looked out the window and into the stormy night. Rain fell in a torrent upon the window, distorting his view of the dark night outside. Alone a small candle illuminated his table, its twin flickering away near the barkeep. As the man grew tired of the pitch-black night, bright lightning burst from the dark clouds, striking on cliffs to the man's northeast and briefly illuminating a lone redoubt on the cliff's peak.
As the thunder echoed, he glanced over at the barkeep. "Rei, whose tower stands on that precipice?" At this, the barkeep stiffened, put down the glass half-polished, and grimaced. A bright flash and the ensuing rage of thunder again shook the small establishment. "Do not go to such a place. It ends well for no one, and poorly for all.", Rei said. Seeing his partner unconvinced, he continued. "You see the Ninetales Redoubt, of the Nine-Tailed Sage."
"Legend tells of a young girl, brilliant tinkerer and mage, here, long ago. In that long-told war of the gods, she railed against them, but was once captured. Rather than death, the god bestowed upon her a curse - to live forever, and in doing so become wise and intelligent, so as to understand the horror of seeing those and that you love eroded by the passage of time. Manifest was this curse, that she bears ethereal dragon's tails, redoubled as time and the curse progress. Such is the origin of her nine tails, and her unspeakable intellect and wisdom.
But this hermit tinker has not borne well the passage of time. She is mad, and passes the years in the creation of countless eldritch abominations. Her alchemy, of half-life, half-metal, it is said, can restore even the beat of a dying man's heart. Yet some desperate fools entreaty the sage, with limbs lost or on dying breath. They become her watchmen and wear grotesque prostheses of metal grafted on flesh and run through with crimson, pulsating fluid. So too, they say, is the sage herself, bearing an arm of metal and piston and an eye of lens and steel.
Those who survive the procedure are thusly bound to the sage, whose hands alone forge the crimson fuel of her prostheses."
Lightning and thunder again shook the bar, with patron and barkeep alike bearing looks both grim and pale. No words were needed to express the message well received.