Featured Game Mode Idea: Skins Add Unique Effects.
It could be fun with a game-mode where the skin you pick gives you an extra effect or ability. For example, Heartseeker-skins could add a charm-effect or something similarly thematic. Battlecast could get an upgradable item similar to Viktor's.
For people without skins they could be given a random skin for their chosen champion over the duration of the match, along with the option of unlocking all of your team's skins for a small RP fee.
If the volume of skins is too much work they could simply restrict the game mode to certain skins. Skin-lines with two skins or more, for example.
Do you think this would be a cool game-mode? What effects could be cool to give the various skins?