How do you get the Shadow Assassin Kayn Icon?
It was a mission or event reward. Riot's description in the client reads: “Earned by completing missions during the release of Kayn.”
Is the Shadow Assassin Kayn Icon still available?
No. Riot tied the Shadow Assassin Kayn Icon to 2017 (mission reward), and it does not normally bring back past event rewards or bundles.
