What should pirate do when thier island was being attacked? They should fight for their glory on defense rather than just hide in a building. So, a guard tower was suggested. A defense pirate unit could stay in the tower. They would come out for PVP fight when enemy apporach to a certain range. It would be good if the unit are donate-based but a new type of guard is also welcome if it is trainable in academy. However, only the Buccaneer and Gunner could be the guard with a max size of 5. They could not active any skills also.