Need to find a manga

So there was this manga I was reading and im pretty sure it was on this site... Its about a young girl who was pretty much born to be a sacrifice for her older sister because she had certain hair or eyes. She apparently had to die for her older sister to gain her dark powers but when they put her in the fire some ghosts or something helped her back out and she awakened her dark powers when she was falling off the cliff. Her dark powers saved her. She then left her bio parents and went to this really powerful lady that soon after adopted her. That was how far I got and I really want to find it again. It had preked my interest. Im sorry if it wasn't a good enough explanation.