You said time after time that Lan will die if Nynaeve dies. What about her? She’s Aes Sedai, so she will live very long. And he’s much older than her anyway. Would she be able to live without him?
Lan is undergoing the severing effect of his bond to Moiraine, which means that he has lost the desire and will to live, which is being restored to him by Nynaeve, on top of which he loves her. If she dies he really really has no reason to stick around. As for Nynaeve, and Lan dying, women are always a lot tougher, emotionally, than men are. Nynaeve will cry for a very long time when Lan dies and she will go on living.
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