Knightfall
World of Kulan DM
How damaging are we talking about? There are A LOT of gods in my campaign so one more, if I take your meaning correctly, won't be a big deal. World of Kulan is very detailed depending on the continent being used. Still, I like to blow up things from time to time.Honestly, in this case I believe you are pretty safe, as I don't recall them using lots of rules. On the other hand, some of the plot twists can be damaging to a world.
There is the demi-god thingie, there is the "mirror" adventure, there is the "tide of years" adventure. All of them good ideas, but if you already have a detailed world, they can sometimes cause problems.
I ran the Shackled City Adventure Path in my world and was more than willing to have the gate to Carceri open, so I can handle earth shaking plots... to a point.
