Hexen II is a fantasy first person shooter made by Raven Software and published by Id Software. It was released in 1997. The game uses a modified Quake 1 Engine.
Note:I was playing with the source port "Hammer of Thyrion" which will make the game work fine on modern systems and allows you to use Full HD resolutions.
Can be downloaded here: http://uhexen2.sourceforge.net/
Hexen II is the last game of the Serpent Rider trilogy (well except for the addon Portal of Praevus ofcourse but I meant the last of the main games ;D ) and this time you are after Eidolon the oldest and most powerful of the Serpent Riders. But before you can get to him you must defeat his generals: Death, Famine, Pestilence and War. You probably guessed it already, they are basically the Four Horsemen of the Apocalypse.
It generally is the same game as Hexen 1 and even uses the "hub system" again where the maps of a chapter are connected to one center map and can be entered from there.
In Hexen II you can still choose from different characters (this time there are 4) but now they implemented a simple XP system where you can level up and get stronger when you kill enough enemies. Every character has different stats and weapons ofcourse.
The game still has multiplayer and is like Hexen 1 a perfect candidate for the coop mode because everyone can play a unique character.