There is a creature in the vast universe known as the Vacuum Dragon. It was a powerful existence capable of creating an area where air cannot flow. It was a creature that needed careful preparation to fight and subjugate.
The Void Dragon was its higher counterpart. Instead of just creating an air vacuum, it flushed out the mana from the directly affected range.
Of course there were several prerequisites in order for this to work without any hiccups. An example would be the needed amount of mana as well as the level of purity.