Well, someone made the Grail and it's some sort of divine, magic artifact. So probably God.

[ He shrugs those broad shoulders of his. Where it came from is immaterial. What's important is the power that it holds and the power that it will provide to the people who in it. However, those thoughts get cut a bit short when Viet reaches up and snags his jaw with a slender, delicate hand. For a moment he's just shocked and then he starts to smile. ]

You are the master. And what are you going to do? What does that mean? Are you going to command me?

[ He's egging her on. Just a little. ]