Harry grabbed his wand, and yelled "Avada Kedavra!"
From Create Your Own Story
Harry felt the rush of power go through him, into his wand, and out came the sickly, green light of the death curse. It didn't matter to Harry now that the same curse he had just cast gave him his scar, or taken his parents away, or stolen Cedric Diggory's life. That has a now far away time, another world, where Harry's compassion, his moral fiber, and his ethics lay. Now, this Harry was different. Something inside him fundamentally changed. He could feel it, pulsing through his veins: the pure rage, the lust for power, the want of total control.
Vernon didn't know what those two words his worthless nephew had said. Something like "Abracadabra", like he had seen magicians do on the telly. His eyes widened in shock as the curse flew at him. And at such close range, no one stood a chance at avoiding the death curse, especially a whale of a man such as Vernon Dursley.
The spell connected with Vernon, blasting him backwards, through the hallway and into the closed, wooden door which led to the bathroom. The door was broken down and hanging from its hinges. Vernon laid crumpled on the floor, a look of shock permanently etched on his face.
Harry stalked up to the body of his uncle. A cold, sinister smile adorned his face. 'That felt... WONDERFUL...' he thought, looking down at his dead uncle. 'Now I understand what Bella meant about needing to really mean it. Harry tore is eyes away from his first victim, and examined his holly wood and phoenix feather wand as if it were a new wand in his hand.
At the sound of the crashing door, Petunia Dursley ran up the stairs. The first thing her eyes saw was her husband laying on the floor. She screamed in terror at the sight. Harry's reflex to the sound was immediate.
"Avada Kedavra!"
The sweet taste of those words left Harry's mouth again. Petunia never saw it coming. The spell hit her, and threw her harshly against the wall behind her. Lily's sister was dead. And to Harry, it felt just as amazing a kill as the first. It seemed his new thirst could not be quenched. Very quickly however, his revelry came to a screeching halt. Harry heard shouting coming from downstairs.
"Harry! Are you alright? I could have sworn I hear the killing curse and screaming in here! Harry, where are you?" Nymphadora Tonks yelled.
Looking around at his dead relatives, Harry had to come to a quick decision...
