Vampires cannot die - they rise, even from ashes.
You can, however, make it very difficult for them to revive. For this you need two: the first to fight the vampire with the force of muscles and strength, and the second to fight with the power of faith.
Saki graduated, but to become a certified Invocator he must pass one final exam. The only shame is that his companion is such a strange one... but then, who could imagine that this puny kid could compete with vampires in terms of strength and speed?
(Source: Translated from Comix-art.ru).