Why.
I played a game of yi. I got first blood. For some stupid reason, riot thought it would be a good idea to make people do an emote when they get first blood. I'm bronze. Everybody in bronze gets upset when you emote them like that. I got 4 manned in my jungle about 10 times that game, and they all kept saying "Emote me again". Do you understand how tilting this is?
also make sure to bind mastery and laugh to easy to spam keys