At the game home screen (Home) click on the "Upgrade" function, illustrated:
Opening condition: Users pass Chapter 1, stage 2, battle 5.
As a place to store information and upgrade support for users in battle, higher-upgrade by Stars are obtained when users pass the Expedition stages:
- Falling Rock: summons a meteor in a custom area to attack enemies, the higher the level, the greater the damage;
- Healing: heals over time for Heroes and soldiers in the custom area, the higher the level, the more healing;
- Ambush: summons a group of sodiers at the pointed location, stuns the enemy in the range, sodiers will attack the enemy in that range, the higher the level, the higher the soldier's stats;
- Crossbow: summon crossbow machine at the pointed location, the crossbow will attack the nearest enemy, the higher the level, the higher the stats of the arrow.