What about a 4v4 team deathmatch/capture the flag arena with a forest surrounded by a tribune and a controll panel hanging from the roof with something to keep it hanging realisticly and redstone "flags" wich would be inside towers and the way you activate it is by using redstone that then will make some lights around the tower light up to show that it's captured ( capturing your own tower would be punished ofc ) and make some traps around.. also have a timer wich would ofc be a giant redstone wall on either side of the arenas. CTF would be 2v2 team fights and team deathmatch would be 4v4 without having to capture the towers ( would have to use the controll panel to disable the towers btw )