Noticed

"So you noticed? As you guessed they weren't vampires like me... Actually they were meant to be like me, but their bodies were too weak to be vampires." Belle explained it casually as if it was a natural thing the children had to accept.

Alicia was a little angry and tightened her grip after finding out what they were hiding behind the plaster. Mark of Possession!

"Are you angry after knowing their destiny? Those who can't help in the war, then they still have to carry out their duty to help the vampires by donating their blood for the vampires." Belle placed the empty glass on the table.

"Blood Servants?"

"No, rather they are a blood supply! So they don't belong to any vampire, because they don't have the Mark of Possession."

Alicia's guess was wrong. The plaster turned out to be useful for covering injection marks and not covering vampire bites.