Elite Skins Upon Max Mastery of a Champion
So i was thinking with the character mastery level now in PBE wouldn't it be cool if they made some sort of "Elite Skin" for every champion upon maxing out the character mastery to make it a more of a feeling that you feel like you deserved and worked towards a skin for playing champions you love. Sure this would take awhile to get to max level of a character mastery but it would give you more of a reason to want to get better at a champion, to want to continue playing games until you unlock the that Elite Skin.
These are just my thoughts of what could make the character mastery more rewarding for summoners.