Phantom

Backstory

Phantom: A figment of the imagination, an appearance or illusion without material substance, as a dream image, mirage, or optical illusion.

I have been dubbed as Phantom. Why? Perhaps it's because I seem like an illusion almost, perhaps because they don't want me to come for them, but most likely because to wish for me to be real, that would be pure insanity. The reason? I am insane, not in the way of a straight jacket locked up in a white cell and laughing my head off insane. A controlled type of insanity, though it comes out sometimes. Blood is the reason for why I live, it's the way I can prove I exist, as long as I have the warmness of it flowing through my hands, nothing else could ever matter. Because of this, I have found the perfect way to kill. Everybody knows that apparating is a way of transportation, but none see just how easy it is to take a liveby apparating.
First though, what is an apparition? A teleportation correct, that is true but no one sees just how powerful it is, especially once you have been blessed by a phoenix and some house elves. These were not easy mind you, but the rewards were certainly worth it. I can apparate anywhere, Hogwarts, Azkaban, it doesn't matter, but I cannot take anybody with me when I apparte, it's just a price I have to pay for unrestricted movement. I can also apparate with a flare of fire, much like a phoenix. It produces real flames, and can be fatal if you are too close.
Back to apparating though, you need to visualize where you want to go correct? Luckily I have been given a very powerful gift since birth, a extremely powerful photographic memory, I can choose when I want to memorize something though, and it comes in handy during fights. To be able to fight, then suddenly apparate right behind, above, left, anywhere near you where my targets wouldn't be able to see me. After that, it's a simple matter of killing the target. A flick of a wand, a snap of the neck, simply bashing in their head, it doesn't matter.
After all, a phantom doesn't exist.