The magic portal to the Ice Queen’s Realm should always be placed in a closet. Optionally, the closet could contain a cloak and the level could contain other references to The Lion, The Witch and the Wardrobe.

Monsters that generate in branches associated strongly with an element (e.g. Gehennom, and the Ice Queen’s Realm) should automatically be given resistance to that element, even if they wouldn’t get it normally.