How Jaime's Death Would Change Game of Thrones Forever

It may seem like Jaime doesn't have a connection to the coming threat of the White Walkers, but his death will have unforeseen ripple effects. For one thing, Cersei will come at Daenerys and her people with every ounce of strength she can muster, and this will pull the khaleesi's attention away from the North, where she is needed the most. As a result, the Night's King and his army will be able to enter Westeros with precious little resistance. They may even find an ally in Cersei if she decides she wants to watch the world burn after losing everyone who has mattered to her.

On a smaller note, the resistance will be down one Valyrian steel sword since Widow's Wail is on Jaime's hip when he sinks.