Champion Mastery Challenges
Okay so we're familiar with the champion mastery through to 7, we play some games and get some S rankings and there you go.
But I think there is room for an amazing addition to this process.
Champion Mastery Challenges.
I haven't ironed out the tiny details but essentially there will be a single solo mission for each champion. To complete the mission inside the time period, the player must use the champion to the fullest. Mechanics will be tested and high scores will be sought after!
For example:
Mastery: 
Get from A to B within 2 minutes. Arcane shift will need to be used to cross obstacles and Mystic shot will need to be used to lower the cool-down of Arcane shift.
A Champion will need to be sniped at the other side of the map using Trueshot Barrage
Targets will need to be hit 5 times before they fall, Using his passive and W to increase his attack speed will be important.
So yeah, room for lots of improvement, just wanted to throw this out there!