The Sage War... That's like the War of the Magi, or "Mage War" from Final Fantasy VI, and Necron... Wasn't he the final, crystaline boss from the Ninth installment of the aforementioned series? ^_^
I think it's a good idea, the trick is to take out those other things and something more original. You introduce it to us as like it's the intro of some movie trailor or video game. It gives a brief history about the past, but says almost nothing about what it turns the planet into. From there, it goes on into what seems like the summary that one might find on the back of a paperback, or like the inside of the a hardcover novel. I think it needs to be more original, but it DID grab my attention, and I DO think it's a good idea.