From what I've read of the story, the light and dark seperation has no lore to back it up. Also my two favorite characters are on different sides. after speaking with a lot of people and hearing a lot of yeses i figured I'd post this here.
Instead of light vs. dark each dimigod would be their own faction and so there would be eight competitors. You wouldn't be locked into one guy though, and favor points go to whomever you are playing as. Because many demigods are used more than others there would be a handicap system, multiplying favor points gained at the ned of each round based on how many people are playing that demigod at the time.
This would make it so there are no demi-god restrictions, fit the plot better, and make a much fairer pantheon system.