New Permament Gamemode and New Champs
I think League of Legends should have a game mode where everyone can be the same champion 5v5 (Summoner's Rift) Where everyone can be the same champ have different roles and just the rest be a normal game.
Also add a group of new champs with some different ability's that we haven't seen yet in the game in the past years. I think everyone will like it and play the game more often.
Message me back if you want more ideas (Only Riot) -LeagueMater