How do you get the Worlds 2023 NRG Icon?
It was sold in the League of Legends store. Riot's description in the client reads: “This icon was available for purchase in the store during the Worlds 2023 Event.”
Is the Worlds 2023 NRG Icon still available?
Probably not. Riot tied the Worlds 2023 NRG Icon to 2023 (store purchase), and it does not normally bring back past event rewards or bundles.
