Gaining Control

Vampires, they call them the undead or the undying for a reason which was why David didn't want to risk it and had immediately pierced the heart of the corpse.

If David hadn't done that, the old man's corpse would be completely overtaken by the personality that had developed overtime from the stain in the organ.

From there, the corpse would wake up as a blood thrall. A mindless monster that only knows how to kill and only sees blood.

By then, it would be a nightmare for David and other students present in the location, as a blood thrall surely had enough strength to wipe out the entire students.

And also for the fact that it would only get stronger the more people it kills and the more blood it drank.

Although it had only been David's speculations, he was really glad he had chosen to pierce its hearts with the wood. Moreover, according to the legends, Vampires are weak to silver and wood, he had chosen specifically to use that method.