Though her swords are clearly designed as piercing weapons, for some reason or another whatever they hit is totally blown away. When Arcueid was hit with a barrage of them in the Ciel route, it was enough to send her tumbling from one end of the park to the other.
This phenomenon is called the Iron Plate Effect. It seems Arcueid assumed that there was some kind of enchantment applied to the swords that caused the force at the moment of impact to be multiplied dozens of times, but in reality this is the result of martial arts and not sorcery. It is nothing less than the Burial Agency's secret throwing technique.

Tsukihime Dokuhon Plus Period - Iron Plate Effect [Unusual talent]