How do you get the Runes Reward Epic Mystery Skin Icon 3?
It was a mission or event reward. Riot's description in the client reads: “Earned during the Runes Reforged 2017 launch.”
Is the Runes Reward Epic Mystery Skin Icon 3 still available?
No. Riot tied the Runes Reward Epic Mystery Skin Icon 3 to 2017 (mission reward), and it does not normally bring back past event rewards or bundles.
