What kind of evil threat does the White Witch represent? How does her evil manifest, and what type(s) of suffering does she cause?

It is important to note that the White Witch was previously the Emperor's hangman, and that it is her right, in accordance to with the deep magic stemming from the dawn of time, to kill traitors.
At the climax of the story, the White Witch battles Aslan, his army, and the children, supported by the evil creatures of the forest. She is killed by Aslan himself.
The White Witch enforces conformity to her evil: a rebellion against Aslan the Christ-figure in the book. People suffer by becoming statues, but the real suffering is being disconnected from Aslan.