Atmosphere Changes on Maps
I have seen the idea passed around that maps could atmospheric changes that could either be random, or based on what champs are in the game.
If it was random, there could could be simple lighting changes for time of day (dawn/dusk/midday), with basic rain particles or super light wind or fog)
If it was based on champions, it would be trickier. I think that GENERALLY each champion could be put into a "good" and "bad" category, and the team comps would sort of randomly generate a fitting atmosphere to the map. (personally I just think it would be cool to have a team of voidborn champs that cause your controlled areas of the map to be darker and creepy, vs a team of light champs with the opposite effect)
Either way, if this existed it should be a toggle effect that would have no negative impact on game play, just something to break up the same old same old