I am not a fan of the faction conflict.
I would prefer that the Alliance and Horde were genuine allies or at worst in a cold war with a few minor scuffles breaking out between subfactions. But the gods of WoW demand that we must fight an all out war, so this is how I start it.
First I would throw out War of Thorns/Elegy/A Good War as the start of the fighting. Before the Storm would stay. I think it’s essential to getting Anduin into a mental place where he would feel a war with the Horde could be necessary. Sylvanas must still be well and truly lost in his eyes.
Azurite and a dying Azeroth are just as important in this story as they are in BfA… so not even slightly.
A war starts between Kul Tiras and Zandalar. Ideally it would be Morally Gray. Neither side is fully wrong or fully right. Old God manipulation or Zul being Zul would do in a pinch.
Talanji seeks help from the Horde and manages to make it to Orgrimmar without issue. She’s desperate. Her father is so focused on the war that he’s completely neglected the problems in his own back yard and she’s certain that without help the Zandalari are doomed. Sylvanas cares little for the plight of the Zandalari, but she sees an opportunity for a powerful ally, someone who might be able to help her in a future war with the Alliance. Even better, the Kul Tiran fallen will help replenish the Forsaken she lost in Legion. Sylvanas is more than willing to send a token force her way, while keeping the bulk of her forces in reserve until she’s fully assessed the situation and how it might benefit her.
Meanwhile, Jaina has been doing some soul searching and attempted to return home. When she arrives she finds her people in dire straights. The war has already taken a toll and the Kul Tirans were suffering from a multitude of problems before it even started. She pleads with her mother to allow her to help. Instead she’s sent away and told never to return. Determined to help anyway, Jaina goes to the Alliance for aid. Anduin is hesitant to get involved in a foreign war, even though the Zandalari have shown themselves to be enemies of the Alliance in the past. And his own people are still recovering from the war with the Legion. However, he can’t in good conscience ignore the suffering of the innocent Kul Tirans. Nor can he ignore the pain of his dear Aunt Jaina who has finally returned. He agrees to send aid. Not directly for the war effort, but to provide healing and supplies and help deal with the various other crises afflicting the Kul Tiran civilians. He knows that fighting the Zandalari will be inevitable, but his intention is to focus on minimizing the number of lives lost.
Neither the Horde nor Alliance realizes when agreeing to aid their new allies that it will lead them into a conflict that will span all of Azeroth, but inevitably their forces clash.
At first it’s just a few small skirmishes. The Alliance is confining their operations to defending Kul Tiras, while the Horde are more willing to help the Zandalari attack.
The Kul Tirans are losing and the Alliance slowly starts to provide more and more support and commit to sending forces directly to Zandalar. The Horde and Alliance are still not technically at war with each other. Not until Sylvanas decides to take advantage of the Alliance’s distraction to attack the Night Elves. Her reasoning–or at least what she tells the rest of the Horde–is that the war between their allies is destined to spill over into their own lands and they need to make sure that it’s on their terms. No one can dispute her reasoning, not even the most peace loving among the Horde.
Teldrassil burns.
Lordaeron is sieged.
The war is officially on.
Kul Tiras and Zandalar formally join their respective factions.
It’s not a perfect scenario. The details definitely need some work. But the basic outline is one I’d find preferable.
Retaining as much of the existing story as possible, how would you start the faction war?