I recently played a game where I lost, and a big reason is because I chose the wrong masteries. I know that as stupid on my part but maybe we can change our masteries before the game. Or we could also change the options. I think it would be cool.
You can change you masteries before the game. You can (no joke) make a mastery page from scratch in champ select if you feel like it. The also give you something like 10 seconds after every champion is picked to change things like skins, masteries, summoner spells, and to a lesser extent runes (as you can only use rune pages made before the game started).
