I think thats a cool idea, but be careful. Without intending on it, you are stroking their egos by singling them out as #1 and needing everyone to join together to take em down. We have this on Baja, 2 large guilds did a cease fire for a couple weeks to take on the biggest pvp red guild, and it was just thrown at us every possible chance. Now that the cease fire is over, it has quieted down, but they still walk around knowing that everyone on Baja had to team up to fight them.