pretty much this. hell, as Demonhunter part of your Order Hall questline even is powering up the Keystone and all if im not wrong. Illidan just used the Legions own housekeys against themself....kinda. there is a gigantic portal above Azeroth now which the Legion propably LOVES since it removes the bottleneck issue of them having had with the Felstorm. they obviously can now just launch everything they have right into the skies of Azeroth due to the sheer size of the portal.
its really going both ways with how it can go.
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makes you think.....how close it again? don´t think that can be good to have Argus blow up at the end with Azeroth pretty much right next to it through the portal.