Back in the old client you would go to the file location, RADS, lol-air-client,releases, then click on the latest folder in that location. It would show you many other folders and one of them being a "Data" folder which in it is in asset which would lead you on to folder that contains all the images of the champions and there skins. Primarily I only used this folder to make a custom wallpaper background of all the cool looking splashes I saw.
And it looked good.
But now with new client, I cannot find it anymore. I ask for anyone who knows it's new location to please tell me where it is?