...I was looking at the magic a bit too critically, and you were just a bit too accepting for us to see the truth. In all honesty, that would be why Battler is the perfect candidate. Smart enough to wing it, but not so smart that he gets stuck like we would.

Magic, in the end, holds a basis in the mind and what is perceived.

And what can be thought of. If you block out all possible conceptions perceived in one's mind of the truth, then it is magic. As long as you can keep thinking, to trick people from seeing the truth of the matter, the magic is real.

And that's why a witch can only die when they stop thinking.