So Ned gets his neck clipped, and in the afterlife of the Old Gods he sees all the events that have transpired from book one – including things he had no way of knowing in his life, like what happens to Daenerys Targaryen.
After this knowledge is imparted to him, some unnamed Old God zaps him back into his own body the day that King Robert arrives at Winterfell. He’s seen what his honor system has wrought, and chaos and death that is visited upon his house. What does he do this time? Is the man capable of capitalizing on this incredible gift?
He realizes that there are more important things going on than the power struggle around the iron throne, and is honour bound to fight the others beyond the wall. Which gets him killed around episode 9 of the first season.
That’s an interesting take! Though he would have seen dragonglass kill one. Calling the bannermen and marching the full strength of the north to The Wall would be epic. That’s much more power than Stannis’ forces - especially if they can source dragonglass for arrows and spears.
Ned knows that Others are real and how to kill them; that Joffrey is illegitimate; that Dany has dragons and is a decent person (at least in theory); how conniving the Lannisters, Freys, and Boltons are; etc.? Ned tells Robert and Stannis about Joffrey. He and Cersei are killed. Robert gets pumped to kill some mythical evil beings, Ned reinforces the wall with 30k men, possibly more, he’d also set people to mine obsidian and outfit the watch with a million obsidian arrowheads.
What of the incredibly pissed off Tywin? If they kill his twins, are they not inviting war? Also, as much as Tyrion is a good guy, he would side against those who executed his brother and sister. If he’s allowed to leave Winterfell, as he’s broken no laws, you’ll have the deadly team of Tywin and Tyrion.
In this case I think he might warn Cersei first (in Winterfell, where he is in control), and allow her to escape with her children (and maybe Jaime)- perhaps on a ship from White Harbor.
