The magic cannons fired in sequence. Hundreds of cavalry units were burned to ash by the shots. The cavalry's formations were not as tight as the infantry's. A weapon like the magic cannon, which were only able to attack in straight lines, wracked up fairly limited kills with the cavalry.
A magic cannon was only able to fire once at a time, and one shot only killed about 40 cavalry soldiers. Seeing there was little to gain by staying, Saleen ordered the demons to retreat.
The three cannons at the front shot accurately. That particular punisher's shoulder finally gave, a crippling wound where the hits landed. Saleen saw white light spilling from the wound instead of blood. The wound began to close in a twisted manner.
If the being hit by the cannons was a living being, the wound would never heal.