Factions and Faction wars
First idea:
Supercell make 2 to 4 faction availables for every clan to choose, if a clan has chosen a faction the clan it self cant leave the faction, faction will automatically reset after the season is ended and must be choose again, faction wars is available once a season (2 week),each faction can only have 50 clans to participate in the faction war, clan that reach a certain amount of faction point will be able to sign up for faction wars, faction point is earned after winning a clan war representing a chosen faction. every faction members will be given 2 chance to declare a clan war againts enemy faction member. when a faction war is ended the winner faction gets an additional xp and a certain ammount of gems to their faction members that participate in the faction wars.
Second idea:
Supercell give an ability to create our own faction, 1 faction must have at least 5 or 10 clan in it to start a faction wars, faction wars will be held for 1 season (2 weeks) where faction members will be facing another enemy faction members, each faction members will be given 2 chance to declare a clan war against enemy faction member. the winner faction will recieve a bonus faction war loot for every faction member that participate and additional clan xp
note:
Faction members is a clan that represent a chosen or created faction