I was thinking again about the night warrior arc and I feel like I missed something, because if I remember it correctly, it was completely useless and did nothing for the story.
What happened?
Darkshore gets attacked, NEs lose
Tyrande goes Night warrior, attacks Darkshore again and contributes to the victory, however not in any extremely meaningful way. She then faces off against Nathanos, who was NOT infused with Jailer power like Sylvanas was. She should have been able to easily beat him even without the NW power, but even with it, she can not kill him.
SL happens and she joins the frey, jumps into the maw and starts killing Jailor forces, which we later learn are basically endless.
She makes it to Torghast and we help her kill the Amalgam of Souls, which again was no impact on anything, except destroying those NE souls so they don't have to suffer anymore. This could also have been done by the maw walker alone, she was just "tagging along"
We then go on a long quest line to help Tyrande learn how to control the Night Warrior Power and in the end she succeeds.
She uses her newfound control to attack Sylvanas and in the last moment before she kills her, for yet unknown reasons she loses her Night Warrior Powers for a few moments, allowing Sylvanas to escape.
We will most likely never know why (remember: Elune only learns about the whole Jailer/Maw situation and Sylvanas much later, there is even a cinematic about it)
We fight Sylvanas and beat her, without Tyrande, and afterwards get the "you have to chose between vengeance and renewal" part, and she basically gives up the NW powers again.
Wtf happened here and why did this storyline exist? What did I miss?