Disclaimer: J.K Rowling owns Harry Potter, not me.

The Half-Demon Sister

Lily Potter woke up from a very strange dream. All she could remember of it was the face of a tall, handsome man with black horns (A/N: No, there will be no Satan in this story). She looked at James, who was still asleep with his messy black hair all over his face.

She got up, and went towards the nursery. Where she found her beautiful son sleeping peacefully. Little Harry was born four months ago. When he was asleep, you would never know that he was also Lily's child. But if you looked at his eyes, it became clear.

In the next day (12/02/1980) Lily had another child. The healers didn't know how that was possible, since Lily presented no signs of pregnancy after Harry was born. No one knew who the father was. Young Kyla didn't look anything like James, or Lily. They even did a blood test on her. It showed that she was Lily's daughter, but it said that the father was unknown.

Kyla had dark brown hair and red eyes. And to make it more weird, she had an inverted pentagram on her right shoulder. At first, Lily and James thought she was a Metamorthmagus because of her eyes, but she never changed her appearance, so they discarded the option. She quickly got along with Harry, and was awfully protective of him.

It didn't take her long to start performing accidental magic, making things float, and suddently appearing at Harry's crib when he was crying. Her parents thought this was very weird. Children weren't supposed to do accidental magic until they were at least seven!

Time-Skip (Halloween)

Lord Voldemort arrived at the Potter's home. He killed James Potter without hesitation, the fool tried to stand up to him without a wand, pathetic. He went to the nursery, where she found Lily Potter standing in front of her children.

"Stand aside, you foolish woman." He said. Lord Voldemort normally wouldn't hesitate to kill a mudblood. But Severus Snape, one of his loyal followers, literally begged on his knees for his lord to spare Lily. And Voldemort rewarded those who were loyal to him.

"NO! Not my children! Kill me instead!" Lily said. If she had to die, she would die protecting her babies. Voldemort didn't care, and in a few seconds, Lily fell lifeless to the ground.

The Dark Lord approaches his next victims. The girl's red eyes didn't leave him for a moment, refusing to miss even one of his movements. The boy had a curious look on his face, thinking that man was actually James in a costume.

But as Voldemort came closer, Harry realized that was not his father, and began to cry. Lord Voldemort hated the sound of children crying, and raised his wand towards Harry.

"Avada Kedavra!" He casted the killing curse. It happened so fast. The killing curse hit Harry's forehead, and the curse went back towards the caster. Kyla could perfectly see a black, spiritual version of the man that killed her parents, being thrown out of his own body and disappearing.

Minutes later, a big man entered the room, it seemed that he was crying silently. He saw the crib, and went towards it.

"Hello Harry, Kyla. I'm Rubeus Hagrid." He said, picking up the kids. Kyla fell asleep, still hugging her brother.

When Kyla woke up, she and Harry were inside a very dark cupboard. Kyla liked the dark, but Harry was terrified of it. She hugged her crying brother

"Mama?" Harry called out to his mother. Kyla shook her head. She knew she would never see mommy again.

A/N: I don't believe in demons, or in the devil, but I find demonology very interesting.