Battle for Azeroth, unlike
Legion, does not have a clear endgame plot or final boss. At this point, many possibilities are open as to who told Vol'jin to appoint Sylvanas as Warchief, and brought him back. Here's a few more words on each possible theory.
Bwonsamdi's boss is a mystery, but as the
Vol'jin questline presents the Lich King as a rival instead of a boss, it's likely not him. One potential theory is that Mueh'zala, the Loa of Death in the children's book
Traveler: The Spiral Path, is the boss. As he wants to "feast on all of Azeroth," perhaps he simply looks forward to more souls as a result of the destruction caused by a warmongering leader. In the
Zandalari Unlock Questline, we see that Bwonsamdi still craves the Warchief's spirit, and what better way to put Sylvanas in harm's way than by appointing her to Warchief, a dangerous position that saw the last two rulers recently deceased. The line about losing a spirit in the past could then refer to Sylvanas leaving hell after "Edge of Night."
Even though the Old Gods appear to distrust Sylvanas in the "
Three Sisters" comic, as the Void urges Alleria to kill her, some upcoming story hints point towards Sylvanas being
very interested in
Xal'atath, Blade of the Black Empire. BlizzCon 2018
heightened the speculation connecting Sylvanas to the Old Gods, between a slide of Sylvanas wielding Xal'atath and the WoW Q&A stating that Sylvanas makes Garrosh look like an amateur.
Datamined broadcast text of
Sylvanas reacting to Xal'atath has strong echoes to the whispers of the Old Gods as well. Perhaps the Old Gods hope to use Sylvanas, encouraging her to weaken both factions as they plot their grand return. Presenting her with a hellish vision of the afterlife, powered by the saronite of the Old Gods, would play into the idea that Sylvanas was tricked into leaving the afterlife, now incredibly paranoid about avoiding hell which then drives her current path of destruction. But Sylvanas could
also be using the power of the Old Gods to benefit her quest to master death, possibly aiming to travel to the Shadowlands with the goal to irrevocably change it, eradicating the chance she could once again die and end up in hell.
With the strong presence of N'Zoth in the Crucible of Storms raid, we've written about the Old Gods pretty frequently recently:
Price of Power - Relics within the Crucible of Storms,
N'Zoth Wants Us to Win,
Hearthstone's Whispers of the Old Gods Expansion in BFA,
Darkmoon Faire and the Old Gods,
Dragonflights of the Old Gods,
Shadreen the Ethereal Watcher and the Master She Serves.
The third angle, that of Sargeras responsible for the whispers, was explained pretty well by Nobbel in the video. The post-
Legion world is a disaster, with all signs pointing to Azeroth dying and the world on the verge of collapse. Sargeras, from the start, has wanted to destroy the planet to save it from corruption. There were hints in
Legion that the Old Gods were gaining strength, for example the
Astromante Etraeus encounter predicts a Void-infested world:
Star Augur Etraeus yells: Is that not enough? Must I show you the true horror of our reality?
Star Augur Etraeus yells: Very well... witness what I have seen, and TREMBLE!
Star Augur Etraeus yells: These are the beings who will devour the future you so futilely fight to protect!
Star Augur Etraeus yells: Avatars of non-existence... knowing nothing but hunger.