If blizzard decide to add a boss after garrosh in siege of orgrimmar, I would find it really epic if they decide to make him really special let me explain.
Lets say you cannot defeat him only make him flee/escape when he reaches a certain percent of health and the boss fight ends, and you will be rewarded with some items of course and a achievment. which you'll need to fight him in the next expansion when you meet him again.
And also to make it not faceroll and unfair for the ppl who earned the achievment in the current expansion, they should scale down the gear when you enter the room to defeat the boss. By doing this they would would make it much more intresting and really Epic experience when meeting the boss again in the next expansion. I hope you see where I am going with this idea and I hope you see my point. cheers.it would be out of the ordinary since I dont think blizzard have ever done that, Imagine a insaely epic escape and should ofcourse still make the boss fight as hard as they normally would.