Dampyr Speciale #1 (2008) pages 130-131: Harpy attack

Radu loses his nerve after seeing the creatures haunting the castle. Vlad Dracula confronts him:

“Radu!”

“Prince Vlad… your highness…”

“Leaving the castle, Radu? You know you can't get away from here.”

“I must! I have to, my prince. You know why!”

“These are difficult times for me to understand… Tell me, Radu. Are you still faithful to the Master?”

“I am. And you?”

“I am part of him since centuries ago, moreso now than ever. Go, Radu. Go.”

(Radu runs but is chased by…) “The Empuse!" (as seen on page 104)

Vlad can't leave the castle because he's not real; he's a projection of his master's mind. But who is his master?