Crazy elite mastery level 8 for one champion only.
Mastery 8 token: only obtainable with champions already level 7 with S grade.
Requires 5 token to upgrade the Champions mastery to 8 but once used, all other mastery 8 tokens for other champions are deleted and no longer obtainable.
The only way to change your mastery 8 Champion should be to de-rank the one you already have back to rank 7, and completely start over with a new one..
I currently have multiple mastery 7 champs and would love to have just one mastery 8 champ to showcase my love for and skill with my main.