How about a new assignment in what ever city you desire with a prize that affects your mob. The item would give you the ability to carry the top 100 strongest mobs you have into battle. This could also be used as a war format for turfs, ops and dm's. On those you would carry into battle only your top 500 mobs. No gear, no sp and no DS weapons. Just the attack and defense of your top 500 added to your attack and defense stats.