Event Game Modes: Roll' Em Rift

So I know we are all super hyped to play URF this year.. I know League does fun event modes every once in awhile..and I wanted to throw out an idea I had for a fun (and troll-y) summoners rift mode. I guess I would call it Roll'Em Rift. The game mode in general? Everyone picks their champions, lanes, etc. However, after every so many minutes, or maybe objectives, there would be a bit of a roulette or dice-throw of randomizing the champions.

Let's say you're Darius top lane.. and then after xxxx (still working out rule/objective) you respawn as your ally Lulu. As far as items go, I would say keep your items. That way it doesn't mess up your build etc. Just would be fun to troll around with randomized champions (between who's in the match, of course).

Thoughts?