I had an idea for a game mode. What about a summoners rift mode where theres only 1 of each item? (excluding starter items of course, like health pots and Dorans Ring.)
So let's say you're midlane veigar against a vladimir. Vladimir buys Rabadons before you; whoops! No rabadons for you that game. And vice versa.
There would be no duplicates of any items other than pots, trinkets, and starter items such as the jungling items and dorans ring.
So you could theoretically build to counter the enemy team by taking away core items for them as well.
The name would be One of All (Kinda like One for All xD)
Another game mode where you pick your champion, but you get random abilities every time you respawn. So you could get anyone's Q/W/E/R. (Imagine Nami surging into lane with Hecarim E. How could you not be interested in that?) It would make for some seriously interesting gameplay, plus it would help newer players and older players alike learn how certain moves can work together for team comps.