I think I understand, as much as I'm able. [Without witnessing it herself, it's difficult to tell. But Inessa has more than enough fodder for nightmares. She doesn't need more.] I have heard tales of demons or spirits taking possession of trees in areas where the Veil is thin. They're called sylvans and can be quite formidable. But that is liable to happen anywhere that enough death or sorrow has happened, enough to make it easier for inhabitants of the Fade to cross over.

The Inquisition's cause is not centered on any Exalted Marches, so you might not be tested in that area. Even so, the amount of upheaval present in Thedas at this time makes such matters difficult to predict.