After the VS. Event..
So the Event is supposed to be which wins and reigns prevalent int he world of Runeterra right? We obviously can't expect Summoner's Rift to become some dark, chaos-infused realm where players can hardly see to play, but what if something actually came from this event? It wasn't just missions, but a permanent piece of the event remained on Rift?
Remember the Ionia vs. Noxus event year and years back that led to the Ionian Boots of Lucidity, marking the triumph? It impacted the game. It made a difference and the world felt real. So what if instead of a new item, the loser's sword (Yasuo or Riven, looking like Riven atm) became sheathed in stone somewhere on Summoner's Rift? Nothing that interfered with the map itself, or a new obstacle to play around, but a trophy of sorts. And then Yasuo/Riven while wearing the skin could approach it and hear a VO line like: "A token of my triumph."
I think that would be REALLY cool.