The best champions out of lane to counter Kayn include Ezreal, Kai'Sa, and Zeri. These are all great at countering Kayn with decent win rates over 56%. Even if these Kayn counter picks are not played in your lane, it's not smart to take him into any of these matchups. They will very likely beat Kayn.
Yet, if the enemy team choses either Teemo or Séraphine, you should strongly consider selecting him, as he easily wins against these champions with win rates over 52% against each ofthem.
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