Evidence Against This Theory
If we accept this theory as true it calls into question everything we believe on the show thus far. Tyrion, Varys, and Ser Barristan all believe that Daenerys is the best hope Westeros has. She has done some cruel things, but all of them were, in her mind, justice. She sometimes ignores the complexities of issues and takes actions that have unintended consequences. This probably isn’t a result of her going insane, it’s probably a result of her being 13 in the books when they started.
Whatever their underlying motives, all we’ve seen White Walkers do is slaughter humans wholesale. The people R’hllor kills are directed by his followers, they specifically ASKED him to kill those people. For this theory to be correct, we would need to pull out the Horn of Winter and an Ice Dragon with no set up on the show yet. All this also begs a serious question: why would Jon want to destroy humanity?
If this theory is correct, Jon isn’t really the good guy either. The White Walkers will still kill a whole lot of people while fighting Dany. In fact, the theory states that they will destroy King’s Landing and that most people in Westeros will die. If we are supposed to be on Jon’s side why would we want him to do this? In order for us not to care about all of Westeros being destroyed, everyone we care about would have to have left Westeros or died (not even counting all the innocent civilians) and that seems unlikely.
What if the theory is correct but in reverse? Before the spoiler images revealed Jon Snow back and definitely human in Season 6, there were a lot of theories that Jon would become a White Walker after his death at the hands of the Night’s King and lead the White Walker army that way. This theory has basically been modified because Jon isn’t looking so icy in that image. But that doesn’t mean Jon will be the same.
Those who are resurrected by the Lord of Light (as Jon likely will be) are known to have major personality shifts (just look at Lady Stoneheart). Perhaps when Jon is brought back it causes a personality shift that leads him to join the White Walkers. In that case, Dany is still the hero Westeros needs and she is fighting back the White Walkers, which have been set up as the greatest threat to Westeros since the pilot episode. The White Walkers could cause massive destruction, but eventually Dany would stop them. That too would be heart breaking (especially since Jon would likely die in that instance), but it would make more sense with the way things are set up.
It’s hard to say how the series will end but a clash between the dragons and the White Walkers seems like a good bet. Jon leading the White Walkers would be devastating and would need to be justified by a major personality shift, possibly caused by his resurrection. In order for Dany to be the villain she needs to become much crazier. She’s done some bad things, but compared to everything else going on they seem totally fine.
For this theory to happen it requires a lot of magical elements to come into play that haven’t been set up on the show and it requires a lot of personality changes for two of its most popular characters. Also this theory has so much going on that it would take a lot of time to explain it. They’d really have to start setting it up in Season 6. A different and perhaps more interesting avenue, would be that once the White Walkers are destroyed, Jon and Dany fight over who gets the throne. If R+L=J is correct, and it probably is, Jon has the stronger claim. Jon might even oppose the Iron Throne returning to Targaryen rule, when his surrogate father fought so hard to get it away from that dynasty.
GoT is all about unexpected twists, but this theory would mean that pretty much everything we know or have come to expect about the show has been wrong. So will this theory happen exactly as stated? Probably not. But we could see some fighting between Dany and Jon, maybe without supernatural armies at their backs. But honestly who can say, there are only three people who actually KNOW how it all goes down and none of them are talking. Game of Thrones returns April 24th, for Season 6. See you there.