In an attempt to figure out what could stop the Night King and his army, we'll look into what happened the first time the White Walkers were around. To forge the flaming sword of heroes called Lightbringer, Azor Ahai needed to make the ultimate sacrifice by plunging his sword into the heart of his wife, Nissa Nissa. It was only after all her soul went into the steel that the sword became strong enough to help Azor Ahai fight off the darkness, thus ending the Long Night.

Now, 8,000 years after the Long Night, the White Walkers are coming back again - stronger than ever, to destroy humanity once and for all. The Night King gathered a massive army with three giants and most importantly - the undead dragon. The Wall is breached, and the dead are marching south, bringing with them the greatest icy storm Westeros has ever seen. With that being the case, one has to wonder, how humanity could put an end to this invasion?

Azor Ahai come again

The ancient prophecy tells us that a warrior shall draw from the fire, a burning sword after the cold breath of darkness falls heavy on the world.

"That sword shall be Lightbringer," the prophecy continues, "and he who clasps it shall be Azor Ahai come again, and the darkness shall flee before him."

As we already discussed in one of the previous articles, Jon Snow is likely to be the reincarnation of Azor Ahai, and Daenerys Targaryen will be his Nissa Nissa. However, there's an issue of Lightbringer, and today, we are going to talk about just that.

Forging of Lightbringer

Before he finally managed to forge a hero's sword, Azor Ahai failed twice. The first time, he went to temper it in water, but the steel shattered just like the second time when he drove the sword into the heart of a lion. Then he called for his wife Nissa Nissa and plunged the sword into her heart, thus finally creating Lightbringer.

What about Jon and Daenerys?

There's no doubt that the tale of forging the Lightbringer will repeat itself. But Reddit user Callews has a different perspective. According to his theory, the flaming sword is only a metaphor for dragons. After all, there are three dragons in our story just as there were three attempts at forging the Lightbringer. The first time, Azor Ahai tried to temper it in water and failed. And the first dragon died in the water, only to be resurrected by the Night King.

If this theory is to be believed, the death of the next dragon could have something to do with the Lannisters, since the second attempt involved a lion. Perhaps Cersei will manage to kill a dragon after all.

Finally, the third attempt will be a success.

Jon Snow will sacrifice Daenerys, and her soul will come into a remaining dragon, most likely Drogon, who will become Lightbringer. Only then will Jon be able to defeat the Night King and his undead dragon in the final battle of ice and fire.