Maxperson
Morkus from Orkus
Defiling magic could be an interesting change for FR. Imagine if the elves all used preserving magic which they taught the humans of Netheril. The Netheril wizards started out as preservers but found they could push their magic to greater heights at the expense of the vitality of the land around them. Instead of the phaerimm (or was it the sharn?) causing the desert it was the Netherese and their overuse of defiling. Now in the current timeline, defiling has been lost or possibly blocked by the goddess of magic much as she blocked the greater levels of spells after Netheril's fall.
Sounds fun!