How do you get the 2016 Worlds Tier 3 INTZ e-Sports Club?
It was a mission or event reward. Riot's description in the client reads: “This icon was the highest tier reward players could earn for participating in the Worlds 2016 in-game festivities.”
Is the 2016 Worlds Tier 3 INTZ e-Sports Club still available?
No. Players earned the 2016 Worlds Tier 3 INTZ e-Sports Club by reaching the top reward tier of the Worlds 2016 in-game event. Riot does not rerun past events, so you cannot earn this icon anymore.
