Allied strongholds must be fortified to withstand assault by Beastman siege turrets. Travel to one of our nation's areas and oversee the construction effort.
Unit Requirement: 1
Talk to the Campaign Arbiter in any zone controlled by Bastok. He will tell you to help fortify the stronghold by handing out crystals to workers. You will not have to provide your own crystals. There are eight different workers who each have a corresponding element (see chart below). Wait until the worker has come to a full stop before selecting a crystal to hand out. The order you hand them out is irrelevant, as long as the worker who needs the crystal you select is on the screen and waiting. If you wait too long, the worker will leave.