Works best with Locks.
Start off by heading twords the bar, you do not need to get the lock open.
At the top of the stairs in the room with the shadowforge lock prepare to run past lots of mobs (shield,renew,healthstone,etc.)
Run straight twords the bar area but head ot the window to the left of the blocked passage, the shortcut to Incend. the mobs wont follow and will reset in a few seconds.
jump down careful to avoid the pat. line yourself up with incend and run through the fire elementals. at the last two stop and kill them. Locks can banish and easily kill them... a priest might need a FR pot.
Now for Incend, around the edge of his room is a little ledge you can run on. Bassically you will kite him in a figure 8 carefull to not let him fall behind and come in front of you.
Shadow word pain and Curse of agony are hat you kite with...will take a few min to kill him, Demo/Affliction locks have the best bet because of demonic sacraficeing your Voidwalker for that added healing and imp. ocrruption for added damage.
Now that incend has fallen to your underhanded tactics you will probally want to hearth or risk running out....or take a swim in the lava and pay for durability... after you get an Ace of elementals the repair bills wont be that bad.
Hope its not too hard to follow.
`Shadowkrosan