Might be spoilers for all books. I never do remember quite well what happened when and I might let something slip by accident. Please read with caution.
Author's Chapter Notes:
Beginning of the story.
Disclaimer: All publicly recognizable characters, settings, etc. are the property of their respective owners. The original characters and plot are the property of the author. The author is in no way associated with the owners, creators, or producers of any media franchise. No copyright infringement is intended.
Chapter 1

A dark clad figure leaned against a blackened tree void of leaves. The hood of its long cape was drawn up to cover the persons face and their hands where folded neatly across their chest. The landscape around them was just a barren as the tree they leaned against. No grass grew, nothing moved but the scorched banches of the darkened trees. And this stretched as far as the eye could see, an everlasting expanse of death, as it had been for the past decade. Voldemort won, that much was obvious. The Muggles had gotten antsy and all it had taken was for Voldemort to mention a nuclear attack on one of the countries to set off a chain reaction. And poof, there goes the world. So, Voldemort got his wish of no Muggles, captured the remaining survivors that didnt support him, and turned the world into his kingdom. Wizards, being slightly immune to the effects of radiation through their dabblings had only minor changes in DNA. Wildlife where pretty much wiped out or distorted to produce lambs with fangs and spider legs or kittens with bat wings.

Pretty sad, but what can you do? Grow it all again? I laugh at you, for this is what is now, and it is known as Morsmordre.

Voldemort has no imagination. Did you expect anyhting less?

The dark figure shook his head and blinked. He was having a conversation with himself again. He pushed off from the tree and started off in a certain direction. The radioactivity had caused clouds to hover constantly over the whole world, making it dark. But not cold for the bombings brought the earths core close enough to keep it from freezing. The figure scrunches up his face 'Get a grip. You know all this already, who am I thinking to?' He reaches up and scratches his white and black haired head, his originally coal black hair had been effected by the radioactivity. No! He was not old! Finally fed up with the talking to himself, he reached up and slapped himself soundly across the cheek, knocking the hood free to expose the face of the boy who lived. Grumbling some more, Harry drew his hood up again and set off at a brisk pace., unknowingly appearing like a certain potions master.

A shiver crawled through Harrys spine and he looked up. Ignoring the looming obsidian castle floating high above and focused on the huge raven circling above his head. 'Foul beast.' Harry thought and lowered his head, darting towards the underside of the castle as fast as he could. But the raven had seen him and was swooping down, talons extended. Harry rolled to the side and the raven missed him, circling around again for another go. Harry started running again, heading for an outcrop of rocks when he heard the cry of the raven again. He turned and dodged again, only escaping the claws by seconds this time. He turned to go back towards the rocks, he was so close! Stopping abruptly when he saw a dark, feline shape hulking there, he backed up slowly. A Panthaera was a decendant of the past big cats. Their eyes glowed red with insanity and their fangs dripped with poison. It lurched towards him and Harry thrust his hand out towards it, his fingertips emitting a yellow light that shot towards the animal. It yowled in pain as the light struck it in the face and Harry felt a tug at his cape as he was lifted into the air by the raven twice as large as he. Swinging limp in the birds talons, Harry smirked, that panthaera would be blind for life.

The raven flew through one of the large windows in the castle, Harry having no choice but to follow.