An idea I had from the night. I am not sure how it will end up, it's a work in progress.
Rain fell from the sky and thunder rumbled occasionally. Inside a large mansion was a young girl. She looked out of a window at the full moon. Her silhouette appeared every time lightning flashed. Each time it changed a little, as if it was approaching her body. A large door opened then shut, the sound of the rain sneaking through the gap and echoing through the hallways. Heavy footsteps belonging to two people grew louder. The lightning flashed once more, her shadow was now poised ready to attack holding two shadow knives. As the two robed men stopped then placed two crystals down. The girl grabbed her head and screamed, kneeling to the floor and bowing her head. Her high scream echoed around each hallway and lasted longer than the girl. She fell to the floor on her left side crying.
One man knelt beside her then went to place a hand on her head but the lightning flashed and showed the shadow going to strike the man with a knife. He screamed, holding a hand to his eye and falling back. Blood poured out from his left eye socket as he crawled to the stones. Another flash, this time his leg was cut deep. His hand outstretched to a crystal but he was smashed against the floor by an unseen enemy.
The other man paled as he shook before grabbing the crystals and ran off. His dieing partner screamed for help but the man just ran out of the house into the rain, not looking back and not wanting to.