1,2, and 3 are the same thing. I expect to see najatar, nyalotha, and so forth during the next expansion. I don't expect argus as its own expac, despite @ravenmoon Fanboying over the shit. Argus is a fel-corrupted base, there's no need to make it its own expac. I could expect us to fight sargeras there, and then go to an expac where the final boss is either a Void corrupted azeroth, or N'zoth....simple...
I expect the Void Lords to die after 2-3 expacs, with a great time-leap during the last...
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I can see WOW not dying anytime soon. Blizzard can make a million other threats greater than our current ones:
Besides, there's enough comic/fiction base material where blizzard can make some swell villains, wanna know who each WOW villain reminds me of:
Sargeras is Kind of Like Freeza (Or, Frieza, if you want to go funimation up in here), with a galactic army, destroying/conquering planets, and more....
The Old Gods seem to reference the Elder Ones From H.P Lovecraft...
Queen Azshara reminds me of a female cell...
Gul'dan reminds me of King Piccolo From DB, with Gokus mind, wanting more power each time he gets some....
The LK Reminds me of Sauron...
DeathWing Reminds me of Smaug....
And The Void Lords remind me of The Outer Gods From H.P Lovecraft...