Etaew Mustache Enthusiast
September,30 2016 16:46There is no guarantee that they'll be added to the game, but I can make sure the team is aware of the submissions. As for sizes, the detail has to be good enough so that it can be displayed in-game. Think of things like the mastery icons above peoples heads, or the buttons in leaderboards.
A guide of 512x512 might be a good start, but make sure it can scale down well to 96x96ish?