I had being thinking a lot to find a setting that will tell a slice of life story, impacted by the arrival of the Legion in Azeroth.
For the moment I can't decide which idea is the best so I keep developping both, I am looking forward to your advice.
First idea is a warlock who set up his tent in the Emerald Nightmare. (I love the atmosphere and vegetation in this place) He brought with him his travelling stuff and research stuff about how to summon a huge demon.
Under his tent, he has drawn a huge demonic circle. In the center of a circle, he has put a table and chair where he sat.
He is losing a game of hearthstone against a deamon (Jaraxxus? :D) The demon is placing a card on the boars with his hand through a small portal and the warlock is like "OH NO NOT THIS COMBO!!"
Second idea is a gnome who set un his excavation site in ruins/desert. He has all his archeology around him. He was meticulously discovering antic skelettons and relics when a Demon relic/inferno/green fire crashed on what he was discovering. There is plague all over the floor, on his antiquities and archeology tools. When he sees the catastrophe of his research destroyed he is like "DAMN MY RESEARCHES! wow anyway this demon relic looks cool!"