Dage's Undead Horsemen, also known as the Four Horsemen of the Undead Apocalypse, are a group of four of Dage the Evil's most powerful champions and most loyal servants. They all serve to test the skills of any heroes in order to help prove them worthy of knowing Dage's darkest secrets. There are four of these horsemen, all of whom serve Dage.
The four Undead Horsemen are all based on the Four Horsemen of the Apocalypse, but they do not actually serve as harbringers of an actual apocalypse. Each Undead Horseman's appearance, personality, and methods of attack are all based on whatever the corresponding actual Horseman of the Apocalypse is associated with. Like the four actual Horsemen, the Undead Horsemen represent Conquest, War, Famine, and Death, respectively.
The four Undead Horsemen are notorious for their incredibly powerful attacks, and reside in Dage's Undervoid arena, whereas Dage mentions the saying, "Abandon all hope ye who enter, because two heroes enter and one hero leaves."