I faintly recall something about how they created an aura of fear to help fuel the magic necessary to perform the Darkhallow. Or something along those lines.

 

Because lots of people have died there over time, and as such there's a large volume of spirits to absorb. They also manipulated human emotion to pull even more spirits out of the woodwork. Fear and panic draw some out that even the Wild Hunt would miss.

I could be completely wrong about all this, it's just what I remember from reading Dead Beat some 5 months ago.

 

You're right, but Word of God contradicts the book. Badly. In the book he makes it clear that the backlash kills people, but in an interview he said that the deaths fueled the ritual.

 

Why does it remind me of a circle: the spirits of the dead are absorbed in the ritual, it create a void which is filled by magic - life energy, so people dies releasing theirs spirits - who also absorbed, create a void... ad vitam eternam.

 

Theoretically, it could do that, until the whole of all life is consumed - except the range is stated to be only a few miles, albeit big enough to take most of the city.

So, I suppose it could work that way, within its predetermined circumfrence. Absorb the spirits, psychically kills those living nearby, who are then absorbed, causing it to surge, a bit. But each time, it would surge less, since it has so much more area to cover - diminishing returns and all that.

 

Honestly, I have to thank everyone who answered. You all were a big help. :awesome