Theres at least one dude out there with level 7 mastery on every champ. Ma5tery or something along those lines.
edit: Actually I see he hasn't finished kayn yet, but he's done everything up to kayns release anyway.
i have 470 total and i only have 1 champ lv 7 and 6 champs at lv6 do the rest of the math 
DRAI