4. When He Killed A White Walker
Season 5 saw Jon making the contentious decision to ride for Hardhome, and attempt to bring the remaining wildlings back to Castle Black. Aside from causing tension with his brothers, there was a much bigger reason why he regretted going. They were attacked, first by wights and then by the Others themselves, and Jon found himself embroiled in a one-on-one fight with one of them. He cannot reach the dragonglass, and is about to be killed when he throws his sword up to block the fatal blow, not expecting it to work. He, along with the White Walker and the audience, are shocked when it does stop it, and he then uses the sword to kill the Walker. Turns out that
Valyrian steel, of which Jons sword (given to him by Lord Commander Mormont) is made, can be used to defeat the Others. The relief is short lived though, when he sails away from Hardhome and is starred down by the leader of the White Walkers, who stuns Jon when he begins to raise the dead.