Huangdi, the Yellow Emperor, knows the importance of having sufficient soldiers to protect yourself. You can use his God Power to duplicate a random number of soldiers in an area. When targeting an army, it can either duplicate a lot of cheap Human units, or a few Myth units. Heroes are unaffected by this God Power.

To use Call to Arms, left-click on the Call to Arms icon, then left-click on a group of soldiers (the larger the better).