Ever since Dany's vision of her brother Rhaegar in the House Of The Undying, which mentioned the dragon having three heads, fans have theorised that we'd get to see each of her dragons being ridden.
The revelation that Jon is a Targaryen only compounded that theorising, and there seemed to be some suggestions that we were going to get to see confirmation that Tyrion too was born of a Targaryen father. After all, his interaction with Viserion and Rhaegal in Meereen could be seen as a direct parallel of the scene in which Jon met Drogon - with the dragons seemingly recognising their kinship in both cases.
With that in mind, it could have been safely assumed that we'd see Dany, Jon and Tyrion confirmed as the "three heads" and all riding a dragon into battle. Except that can't be the case now, because we've lost a dragon.
With the death of Viserion in 'Beyond The Wall', the prophecy of the three heads has changed dramatically, and it seems we're unlikely to see Tyrion ride a dragon at all. It might still be the case that he's a Targaryen (how else would the show explain how he wasn't eaten when he went under the pyramid?), but he's lost his mighty steed before he's even had a chance to mount it.
The reason it's possible to say with such conviction that it's Tyrion who will miss out is down to the link between Jon and Rhaegal. The dragon is named after his father, and just as Dany chooses to fly Drogon primarily because she feels a closer bond to the creature named after her first love, you'd expect Jon to ride the one linked to his own past closely.
Interestingly, the prophecy could still mean we'll see another Targaryen family link revealed. If that "three heads" line does indeed mean three Targaryens, you have to assume that the Night King himself shares the same bloodline as Dany and Jon. It's inevitable that he will now ride the resurrected Viserion (there's no way you set up an ice dragon without letting him climb aboard) and that might just be the confirmation we need.
There's definitely more to come in the backstory of the Night King - specifically focusing on who he is and where he came from - and this could just be one of those world-changing twists. It would certainly explain the way he looks at Jon Snow every time he encounters him - with that mix of intrigue and familiarity.
Then again, we could be reading the prophecy wrong, and focusing on the wrong element. The three heads might not be a reference to Targaryen, but a different link between the riders entirely. Each of Dany, Jon and the Night King represent something different (fire, ice and a mix in Jon's case), and that might be the important relationship between them, in which case the popular theory that the Night King is a Stark could still come into play.
What do you think? Is this the end of Tyrion as a Targaryen as well as as a dragon rider? Could the Night King be a Targaryen? Share your reactions below.