In the world where William resided, talented RTS professionals were able to give orders to hundreds of units with ease through their impressive multitasking abilities. There were even extraordinary players who were able to flawlessly micromanage every unit in the midst of a chaotic battle.
William possessed unparalleled willpower and computational power, allowing him to easily control his Mirror Shadow clones with just the movement of his fingers.
He would switch his perspective on the battlefield constantly, calculating the casualties on both sides as he commanded his one-man army to take on the other party's seemingly endless legion.
(#4, #37, we need to reinforce #2 who's currently facing Carnage alone.)
(There are too many soldiers. #4, use the Storm spell, Howling Wind, to clear a small area.)