How do you get the Master's Challenge Season 2?
It was a ranked reward. Riot's description in the client reads: “This icon was earned for participating in the Master's Challenge event in China.”
Is the Master's Challenge Season 2 still available?
No. The Master's Challenge Season 2 was a ranked reward: to get it you had to reach Master during Season 8 (2018). Riot does not give out past ranked rewards again, so it cannot be earned anymore.
