The goal: Send everyone into the middle area and ignore the dominion game rules. If you are killed, reenter the arena as quickly as possible after buying items. (Disallow item purchases until death.). Picking up buffs are OK. The game continues until a set score [first team to 50 kills] (or if Dominion mode ends through natural causes.).

I'm not sure if CS would be admissible, but this would be a new flavor mode.

Teams do lose a point when a champion dies... but you're talking about 500 deaths for champion deaths to cause a defeat, and I'm not even sure if Dominion will have a surrender option, considering how fast the games are supposed to play.