How do you get the Dominated Dominion Icon?
It was a mission or event reward. Riot's description in the client reads: “Players who had 100 or more Dominion wins the Dominion game mode was retired in 2016.”
Is the Dominated Dominion Icon still available?
No. Riot tied the Dominated Dominion Icon to 2016 (mission reward), and it does not normally bring back past event rewards or bundles.
Dominated Dominion Icon is one of the rarest LoL summoner icons.
