The Elemental AOS
4-way AOS action, pitting Earth, Air, Fire and Water against each other.
Each has their own temple in the four corners or centers of the map, with Fire opposite from Water and Earth opposite from Air. Fire MUST kill Water and likewise, and Earth MUST kill Air. When a team is completely obliterated (we'll say Fire takes Water out) then Fire's influence over the Water Spirit modifies it and creates a half-breed that fights for them. First team to have power over all of the domains takes it. To control a domain, there should be some sort of trigger unit that players only get one of (respawnable) that has to enter the domain and stay there for X minutes. That's just me, thinking... another similar option would be War, Death, Plague and Famine (The horsemen of the apocalypse)
My apologies for not staying linked entirely. The main reason is because my WorldEdit keeps freezing. Yes, I've uninstalled, reinstalled, all that jazz, but it freezes after about 2-20 minutes of work, so I have to save every 30 seconds. It's a downer. That and college.