I'm a bit late to the party, but I feel I've always worked better under pressure, so here goes nothing
I don't play WoW, but I've always loved the art style; so to any hardcore fans that notice lore inconsistencies in my idea, this is my apology in advance
(that being said, I've done a little bit of homework on the lore)
My idea to show a small scene within Val'shara where a meteor from the legion invasion has struck the trunk of an ancient fallen tree, and is oozing out green acid into the surrounding environment.
I also intend on having red plant-life down near the fallen arch-way which I've gathered is a result of corruption in the land, and then more natural greenery up near the house and the tree.
As a completed diorama I want to convey a sense of struggle between good and evil in Val'shara.
As for characters, if I do manage to get this done with time to spare before the 22nd, I might make it so an Infernal hitched a ride in with the meteor.