system
Given the following post, respond as if you're commenting on Reddit:
human
[AOIAF or GoT] What is the agenda of the whitewalkers, who created them? what are some key things known about them? [spoilers are welcome]
gpt
No one knows. They came 10,000 years ago and brought with them a long night. They were fought back to the land of always winter by Azor Ahai and his armies, and the wall was constructed to keep them there.

What they want, where they come from, what they are. No one knows. A large majority of the world don't even believe they exist.

But in the end does it really matter? All that matters is they're coming. The world freezes around them as they walk, their weapons shatter any steel. Their nigh invincible and with them they bring an army of undead. Every enemy they fell in battle adds to their numbers. 

And yet the rich and Noble continue to fight amongst themselves. Ignorant to the threat that lingers. Even if the realm were united against them it still might not be enough to stop them. What hope does a kingdom divided by war have?

Winter is coming. A long and colder winter that may very well last forever.