My theory suggests that Daenerys Stormborn of the House Targaryen is Azor Ahai and Aegon a.k.a. Jon Snow is the lover, Nissa Nissa. The three dragons are three attempts and thus one more dragon is to die.
Remember how Azor Ahai forged his lightbringer? There were three attempts.
As the legend says, “Darkness lay over the world and a hero, Azor Ahai, was chosen to fight against it. To fight the darkness, Azor Ahai needed to forge a hero’s sword. He labored for thirty days and thirty nights until it was done. However, when he went to temper it in water, the sword broke.”
Towards the end of Season 7, we saw that Viserion died and drowned into the icy sea. Viserion broke. Thus, the first attempt was in vain.
The legend continues, “He was not one to give up easily, so he started over. The second time he took fifty days and fifty nights to make the sword, even better than the first. To temper it this time, he captured a lion and drove the sword into its heart, but once more the steel shattered.”
We know that the lions are the symbol of the Lannisters, and more specifically Cersei Lannister, thus Rhaegal would be the second dragon to die. As many have predicted, Cersei might become the Night Queen and thus become elemental in killing Rhaegal, the second dragon.
Further, it may so happen that John gets severely injured and dies, and then returns as a wight. Daenerys does what is necessary and burns him with the help of Drogon, thus the sacrifice made and hence Drogon, the lightbringer is ready to end the long night and slay the Night King/Queen.
I personally think, this might happen as Nickolaj Coster-Waldou ( Jamie Lannister) said in an interview said that in Season 8, we may see some major characters turning into wights and John is one of the most important characters.
In short, Daenerys is the Azor Ahai a.k.a “the prince/princess that was promised” and Drogon is the Lightbringer.
What do you think about this theory? Tell us in the comments!