"Disable Mastery Emote" settings please.
So nobody gets tilted when the enemy yasuo or zed flashes their emote every time they can.
Please. Just let there be such an option.
Please note that by disable I mean a setting in the game setting interface which says "Disable Mastery Emote" or something similar. So others can definitely see your mastery emote if they have that settings turned off, and if you have it on you won't be able to see mastery emote.