The Castle can accumulate XP after you have played a 1 vs 1 challenge or a daily challenge. Then you can use those XP to upgrade the items in the Castle to make it stronger. This helps you to breathe easier in upcoming battles and increases the value of the Castle in the market.
To upgrade the Castle, please follow the steps below:
Step 3: In the game main scene, please select the "Upgrade" button from the bottom menu, or select the Castle's avatar on top.
Step 4: In the upgrade scene, please select the item that you want to upgrade from the side menu.
Step 5: In the Item scene, please select the upgrade button to upgrade the item.
Note: Please make sure that the Castle has enough XP for the upgrade.