The more I watch Game of Thrones, the more I feel like the series' original title, A Song of Ice and Fire, might be more appropriate. If anything, it's a fitting clue about what to expect in the show's final episodes. While the White Walkers and Winter itself are clearly the "ice" element, Daenerys's dragons might not be the only "fire" elements the Night King should look out for. Dragonglass, a substance forged from volcanic lava, is one of the most powerful materials in the entire Game of Thrones universe because it's strong enough to take down a White Walker. But what about taking down the Night King, the very first White Walker? That isn't so simple.
What Is Dragonglass?
In season six, Bran travels back in time and witnesses the birth of the Night King beneath the weirwood tree by the hand of Leaf, one of the Children of the Forest. Leaf stabs the Night King — then one of the First Men — through the chest with an obsidian dagger, aka dragonglass. Obsidian is a naturally occurring volcanic glass (definitely more fire than ice) and has been shown to effectively take down White Walkers, which Sam demonstrates in season three when he finds a bag of dragonglass beyond the wall and uses it to kill a White Walker.
Back in season seven, after some dragonglass research, Sam clues Jon in on the fact that they can probably dig up shiploads of dragonglass on Dragonstone, the ancestral island of the Targaryens, which results in Jon teaming up with Daenerys so she'll allow him to mine enough glass to arm his men. Battleaxes, hatchets, daggers, and more have since been created and used to hunt down wights and White Walkers. Even Arya has armed herself with a custom spear made partially from dragonglass, just in case her tiny Valyrian steel dagger doesn't quite cut it.
What Other Weapons Might Kill the Night King?
Valyrian steel swords are the only other weapon that have been proven to effectively kill White Walkers. Even if the Night King isn't susceptible to dragonglass, Valyrian steel, a rare and ancient material, could ultimately be his weakness. At present, only a few characters have Valyrian steel weapons, including Jon Snow (Longclaw, given to him by Jeor Mormont), Arya Stark (an unnamed dagger given to her by Jon), Jorah Mormont (Heartsbane, given to him by Samwell), Jaime Lannister (Widow's Wail, originally King Joffrey's sword made from Ned Stark's Ice), and Ser Brienne of Tarth (Oathkeeper, also made from Ice, previously used to defend Sansa Stark).
Will Dragonglass Kill the Night King?
If this were some frozen zombie version of Rock, Paper, Scissors, we might be able to say that fire automatically defeats ice, right? After all, ice melts in fire. But, if you argue instead that water puts out fire, then things start to get a little more complicated — and we all know nothing in Game of Thrones is ever as simple as it seems.
While the Night King is considerably more powerful than the rest of his army because he's the first of his kind and pretty much the embodiment of death itself, it's possible that the White Walkers' vulnerability to dragonglass is a side effect of being reanimated by the Night King. Dragonglass gave him his powers. In this same vein, if dragonglass can take down his undead army, then maybe another shot of obsidian through the heart would be enough to reverse the effects of the original stabbing and take down the Night King once and for all — unless someone wielding a Valyrian steel weapon gets to him first.