Nexus appearance change
I feel that the nexus dose not relate to the game other than a building. The Nexus holds no story of its own, but if you were to redesign the Nexus, so that instead of random mages floating around, you could have custom summoners drawing power from the nexus to summon you, after you destroy it the summoners vanish as they are sent back to the End of Battle results. this would allow you too interact with the League of Legends out side of the fields of justice, other than Icons, and add lore to the game itself.
Also, I think there should be the ability to access a chat menu during the load phase.