Having been reminded by Jounouchi Hiromi, Chen Yu realized that he had indeed searched for the wrong entries.
For a Necromancer, there is no such term as a "vegetative state." To Necromancers, brain damage is just brain damage, and soul separation is just that; they do not entertain the concept of a vegetative state. Persistent comas, to a Necromancer, are defined and categorized differently based on their causes and are not all lumped into one group.
This was why Chen Yu had failed to find any information on vegetative states—he had been thinking with the mindset of a medical doctor and had only searched for information on that subject, hence finding nothing relevant.
Since Necromancers do not recognize the concept of a "vegetative state," naturally, when Chen Yu searched for information on it, he couldn't find anything.
Once he realized his mistake, Chen Yu changed his search queries, and this time he quickly found the information he had been looking for.
