After taking more milk of the poppy, King Viserys is once again delirious and unaware of his surroundings. In this delirium, he speaks to Queen Alicent, who he believes is actually Princess Rheanyra, and brings up the prophecy of Aegon the Conqueror once again: “From my blood come the prince that was promised and his will be the son of ice and fire.”
Alicent, who had no idea about the prophecy or the dream, assumes that he’s talking about their son as he says, “To unite the realm against the cold and the dark. It is you. You are the one. You must do this. You must do this.”
It’s funny to think that a drugged king and a misunderstanding of Viserys’ final words would become the catalyst that would lead to the civil conflict in House Targaryen and its ultimate destruction.
Fans of Games of Thrones will already know that the cold and dark referred to in Aemon’s dream is the threat from the North beyond the wall: the Night King, with a touch cold enough to burn through visions and shatter weapons, and his horde of White Walkers.
The undead creatures of pure ice were originally created for battle. Together they have one mission and one mission only: to once again bring about an endless night and destroy the world of man and everything that lives in it.
Aegon dreamed that the only thing that would save the people from the absolute darkness was a Targaryen from his bloodline that was strong enough to unite the realm against the threat.
A lot of people might have assumed that with Daenerys being the last Targaryen she would become the “prince” that would unite the realm against their enemies. She shared the same belief, shown in her attempts to finally claim the Iron Throne for herself and House Targaryen once again, but there is another Targaryen on the playing field: Jon Snow.
Given that he is the trueborn son of Rhaegar Targaryen (which gives him a stronger claim to the Iron Throne) and he was the one that led the troops of Westeros against those of the White Walkers in the battle, it seemed to further confirm that he was the king Aegon the Conqueror dreamed of (and who Viserys was referencing in his last words). The two of them even shared the name Aegon.
There is the small matter that Arya Stark was the one that ultimately defeated the Night King and brought victory to the realm rather than its prophesied prince, but that was a choice made by the showrunners who thought Jon defeating the Night King would have been too predictable (Arya fans aren’t complaining though).
Unfortunately for the fans of the Mother of Dragons, she was not the prophesized “prince” and was therefore never destined to sit on the Iron Throne. So it’s doubtful that Viserys’ last words point to Daenerys Targaryen.