Can Helaena Targaryen Really See the Future in House of the Dragon?
The Targaryen family, being Old Valyrian nobility survivors, had always possessed a number of strange powers that separate them from normal men.
Some of them are undeniable including their ability to bond with Valyrian dragons and their resistance to fire and heat.
Some might be only rumors and legends, which ascribed more mysterious powers to people who already had mysterious powers, including their alleged immunity to infectious diseases and the power that is supposed to be rare and exceptional even according to tales, passed down in the family itself – the power of future sight.
King Viserys, who was quite concerned with matters of prophecy and fate, believed that he saw the future once, and also believed that the founder of the Targaryen dynasty, Aegon the Conqueror, also could see the future, and left a prophecy for his descendants.
But Viserys' vision was vague enough to be just a vivid dream, and Aegon could have issued the same warning thanks to learning of the past, rather than seeing the future (certainly, going by what happened in Game of Thrones, his prophecy ended up wrong in those details, which actually demanded future sight, rather than mere information on the threat beyond the Wall).
There is another candidate for seeing the future in the dynasty by the end of House of the Dragon Season 1 – Viserys' daughter, Helaena Targaryen.
Helaena is often believed to be not quite right in the head, and prone to talking weird-sounding nonsense, so few people ever listen to her. But more than once, gibberish that comes out of her mouth ended up pointing out to the future events.
When Aemond tries to claim a dragon, Helaena tells her mother, "he'll have to close an eye" to become a dragon rider. And Aemond gets his eye slashed out by Lucerys on the very night he claims Vhagar.
Then Helaena warns her family to "beware the beast beneath the boards" before Rhaenys and Meleys burst out of the ground in the Dragonpit. Indeed, Helaena's questionable relationship with sanity in itself might be a sign of her prophetic abilities.
After all, George Martin is prone to writing all magic as mysterious, unknowable and dangerous to one's body or mind.
And A Song of Ice and Fire had already included a prophetic fool (the character, Patchface, was omitted from the Game of Thrones TV series), plus a number of prophesies which seem to be so figurative and vaguely formulated as to be useless in practice, just like Helaena's predictions. In fact that is another reason to doubt the prophecy of Aegon the Conqueror – it is way too specific and clear-cut for Westeros.