How do you get the 10th Anniversary Summoner Icon?
It was a mission or event reward. Riot's description in the client reads: “This icon was awarded for playing during League of Legends' 10 Year Anniversary event!”
Is the 10th Anniversary Summoner Icon still available?
No. Riot tied the 10th Anniversary Summoner Icon to 2019 (mission reward), and it does not normally bring back past event rewards or bundles.
