She was a ghost. That is the only thing she knew when she awoke in the woods, floating above the newly dead body of a young woman. She could only assume that the body below her was her own, but she couldn't be certain. She started to look around for the killer, and then quickly realized she couldn't see anything. She could sense the body below her and the trees nearby, but she couldn't actually see them, as she had no eyes. Neither could she hear anything and she immediately recognized this to be a major hindrance to her finding the killer. She noticed a bird in a tree close by, and without really understanding what she was doing, reached out and seized hold of its faculties.
Now seeing through its eyes and hearing with its ears, she spread its wings and took off in search of the killer. Through its ears, she could hear the distant sound of someone running, and turned the bird in that direction. The bird was able to overtake the runner rather quickly, and without much thought, she leaped from the bird to the runner. As she neared the head, a blazing network of interlocking symbols flashed into being between her and the runner. Upon contact with the symbols, her movement was arrested and she felt a burning sensation. Enraged, she beat against them with such a fury that the symbols seemed almost to give off a sense of surprise. She took advantage of this perceived weakness and struck out with all her might, shattering the network of symbols and proceeding into the mind of the runner.
She was hit with a cacophony of thoughts and emotion as she entering the runner, who was a man and former friend of the woman whose body she had awoken over. The woman's name was Claire, and the man's Tristan, but she knew almost immediately after learning this that she was not the woman. Tristan's thoughts told her that she was a spirit of vengeance, and he was the target of that vengeance. His feeble mind was easily overthrown and after stopping his movement, she began search for a way to kill him. It just so happened that he was holding a knife, still fresh with blood and engraved with a single rune. She stabbed him in the eye with it until his body gave out, and she felt his spirit leave, screaming in anguish.