Calter's chaos balls have unbelievable power. It can literally suck and rip to shreds anything that it wants to. When the debris entered the chaos balls, they would then be thoroughly destroyed until nothing would be left from them anymore
This is what he was going to rely on when fighting against a large number of enemies that were weaker than him
The zombies might have been powerful but that is only compared to normal humans and those that have weak magical skills
To people that are experts in magic, the zombies aren't that much. However, even a magic expert wouldn't necessarily be able to defeat the lich controlling the zombies
As for the reason? It is simple. The sheer number of the zombies made it near impossible for a single person to defeat the lich
After all, there were thousands of zombies under the lich's control. How can a person easily defeat them?
