"An expansion pack called Hexen II: Portal of Praevus was released in 1998 featuring new levels, new enemies and a new playable character class, The Demoness. It focuses on the attempted resurrection of the three Serpent Riders by the evil wizard Praevus, and takes place in a fifth continent, Tulku, featuring a Sino-Tibetan setting.
The expansion featured new quest items, new enemies, and new weapons for the Demoness. She is the only player class to have a ranged starting weapon, whereas all other characters start with melee weapons.
It also introduced minor enhancements to the game engine, mostly related to user interface, level scripts, particle effects (rain or snow), and 3D objects.
Portal of Praevus also featured a secret (easter egg) skill level, with respawning monsters. The only released patch for the expansion added respawning of certain items (such as health and ammo) in Nightmare mode, so that it would be slightly easier for playing."
Source: Wikipedia, "Hexen_II," available under the CC-BY-SA License.