Originally Posted by
Linkedblade
Well technically Neltharion the Earthbinder (Deathwing) was left to watch over the world to make sure no one hurts the planet itself. He was supposed to keep the world as close as possible to it's Emerald Dream cousin.
We aren't going to kill all the aspects. In fact 4 of the original 5 remain alive, and Malygos, whom we adventurers killed, is being replaced by his son Kalecgos [Possible Speculation].
Neltharion want to all ends to help protect the planet, even going as far to create the Dragon Soul, which was formed in a metal disc, with power from all of the aspects. But as it would go Neltharion would slip into madness, and use the Dragon Soul on everyone at the end of the War of the Ancients, killing the entire Blue Flight except Malygos, drinving Malygos into a depressed manic mental state. Neltharion was corrupted by the Old Gods, which is why Neltharion and Ragnaros are teaming up, they are both controlled by the Old Gods. I doubt that Alexstrasza, Nozdormu, or Ysera will fall to the Old Gods, even so a member of their brood could stand up and take their place.
Now the Old Gods were inprisoned by the Titans. Eventually their cells have weakened and they have enough power to control some mortals, who then find more and so on. C'thun used his power to create the Twilight Cult who helped to free him, but we adventures kill him before he did any large form of damage to the planet. Yogg'saron we stopped before his influence spread to any sentient life beyond Furbolgs.
Actually I think by killing the Old Gods physical forms we are actually releasing them from their true prison, which is their physical form. One titan has actually been corrupted by the Old Gods, that one being Sargeras who just happens to be the leader of the Burning Legion.
Here is Azerothian Pantheon:
Old Gods/Titans > Dragon Aspects > Elementals > Demigods > Mortal Races
So really Sargeras would be easy to take down, he's only a single titan, if we had backup we could take him down, his Legion consists of nothing but mortal races. In Ulduar, we has Titan Backing against and Old God, and that should make Deathwing sound like an easy fight.