All the monster spawn in Ilshenar, both over land and dungeon, has been increased 2x its normal amount.
All the spawn in Ilshenar now has a minimum respawn chance of 1 second and a maximum respawn chance of 2 minutes. (faster re-spawn times than the other facets)
Some previous locations may be much tougher now. While others that were never used due to low spawn rates may be worth seeking out.
The only exception to these new changes is the Twisted Weald.