There are written rules that have been taught to every knight who fights Shadows. The knights were not allowed to face them in the middle of a residential area. If forced, there must be other knights who lead the civilians away or hide. They also had to kill them as quickly as possible because Shadows were created to do mischief.
They attack without reducing strength. They crush and crash into anything they come across. Pure-blooded vampire knights usually could balance them out. But not with Shadows type C. They were smarter and more powerful. They were even capable of rapid generation.
Even the knights with high rank like Caesar and Raphael's had a hard time dealing with them. Valerie almost lost and had bad luck if her brother Jasper didn't come in time to kill it.