Champion Mastery tweak

Champion mastery is such a cool thing Riot has added, but i feel after awhile everyone will just have all their champs lvl 5 and it wont be something we awe at anymore. I think what would be a great idea would be to extend the champion mastery to a lvl 10 and harder achievement, but at lvl 10 implement a mastered skin for the champs you get to lvl 10! How cool would it be to put in lots and lots of games to reach lvl 10 and get a "Mastered Azir" skin or a "Mastered Tryndamere" skin. This I feel is a good way to keep people playing and attracted to the game and encourages people to continue to play their best, instead of bm. I do understand making a Mastered skin for every champion would take a looong time but i still feel its a good idea.

If a rioter could reply with their thoughts that would be great.