We don’t know much about what they are, but we do have enough content to at least understand a good deal of it. There is the Night Warrior (the moon phase), the Night Warrior (Tyrande), and the night warrior (the new black-eyed elves). We know that night warriors are widespread. In the warfront, all generic NPCs are night warriors - established characters such as Thisalee Crow (who unfortunately survived Legion) and Jarod Stormsong still have normal eyes. This could either be an overlook, or more likely, a sign that this is a widespread thing now.
But what do we know about the other Night Warriors? First we will look at an archaeology find, and then (reluctantly) turn to the wiki.
Necklace with Elune Pendant
Elune is the primary goddess of the night elves. She is associated with the larger of the two moons, the White Lady. While she is a goddess of peace, she is not a pacifist. One of her aspects is the Night Warrior, who takes the valiant among the dead and sets them riding across the sky as stars.
So, the Night Warrior is just an aspect of the moon and, naturally, Tyrande comes to embrace this side.
But let us now turn to the gamepedia, which will give us all the information possible to compile on these elves! Perhaps there will be something of note.
Night Warrior
Strongly associated with healing, tranquility and harmony, Elune is a goddess of peace, but she is not always a pacifist, as she does not advocate peace at all costs. One of her aspects is the Night Warrior, who takes the valiant among the dead and sets them riding across the sky as stars. The Night Warrior is the incarnation of Elune’s wrath. The ritual to become the avatar of the Night Warrior is extremely dangerous, and even witnessing it puts you in danger. Legend says that long ago, the Night Warrior was used by the night elves to carve out their empire. None who have attempted the ritual since then have survived, for Elune’s raw power tears them apart.
During the Blood War, Tyrande Whisperwind survived the ascension to become the Night Warrior. Not only was she empowered but many other night elves were as well, forming the Army of the Black Moon, Elune’s power in an unnatural, seemingly eternal, night.
The description of the Night Warrior taking spirits of the departed into the sky as stars resembles what happened to Ysera upon her death.
Unsurprisingly, really nothing new. This brings me to the conclusion that Night Warriors only really served one new purpose in the plot - to try and make Night Elves more Warcraft 3 again. Tyrande is back to doing what she likes and defying orders (though that never really changed), Malfurion is coming back to save the day, the Horde is the sole enemy, elf against Forsaken. They’re just a bad plot device that look cool to return to the past.
At least, that’s my thoughts on the entire thing. I might have dragged that out longer than I needed to, but that’s really everything I could find on the Night Warriors.
What do you think?