Ok, in The Battle for Mount Hyjal instance, you can make the archimonde fight slightly easier by positioning your entire raid on the root of the world tree, thus allowing you to dodge doomfire
1. Hug the well of eternity, walking towards the root directly infront of archimonde, being careful not to slip in
2. get your entire raid to stand at
making sure your below a root so when you get air bursted, you hit the root above you (as shown in the pic)
3. Have your tank stand on the **grass**, because if your on the root, or anyone on the root pulls agro, archimonde will finger of death everyone, and have a hunter stand with the tank **on the grass** and MD pull
4. dps him down, you will still get feared, shamans are good to avoid this with tremor totem
Tip: Rogues are useless, try to stack ranged dps + shamans for tremor
And of course, by doing this, the doomfire doesnt go up the root, making the fight easymode, gl