Challenge/Reward system

Since the creation of Champion masteries I feel like there should be a challenges system. For instance there could be general daily challenges like play a support 3 times or get 5 double kills. Then there would be specific champion challenges such as Thresh: land three hooks in a row without mission or Vayne: Go afk for 50 games. Rewards could vary from Ip, Ip boost, Ward skins, Icons and mystery skins/Champions.