Dominion FFA Featured Game mode?

Had a few game mode ideas floating around in my head, Namely 6-8 player free for all on Dominion. Likely based on kills as the objective - Which seems like the only format a kill based objective would be fun enough in. Also for Summoners Rift, maybe something like every time you respawn you get a new, random ultimate. Or like every 90 seconds everyones ult changes and cooldown is reset? could be fun, or atleast an interesting place to start.