How do you get the Gun Goddess Icon?
It was sold in the League of Legends store. Riot's description in the client reads: “Acquired by purchasing or unlocking the Gun Goddess Miss Fortune ultimate skin before the end of the Gun Goddess Miss Fortune event.”
Is the Gun Goddess Icon still available?
Probably not. Riot tied the Gun Goddess Icon to 2018 (store purchase), and it does not normally bring back past event rewards or bundles.
