At random, Clan Battles will have the rules change to a free-for-all mode called Battle Royale. You cannot initiate this and it is completely random. Colors will disappear from all players names and everyone becomes a target. Come out on top when time expires to score the achievement. The easiest way to ensure this happens is to not be drawn into the melee. Instead, wait for everyone to congregate and unleash a Ninpo attack at everyone. Bear in mind that others will look to do this too, which leaves them wide open for a Ghost Attack! See the Sneaky achievement for more information on this move. Online MP only!