Apocolypse(黙示録) is a series of Dark-Attribute monster cards introduced in Pit of Oblivion, themed after the Apocolypse in the Book of Revelations. Each card is designed to be weak by itself, but when joined with other Apocolypse cards they become stronger and stronger. The support cards focus around the use of Apocolypse Counters for control of the field, while the rest, namely Beast and the Horseman, focus on power and control.
Horseman of the Apocolypse(黙示録のホースマン) is a sub-series of the Apocolypse cards, themed after The Four Horseman of the Apocolypse. All six are Level 7 Dark-, Warrior-Attributemonsters that have 1100 ATK and 1050 DEF. Each possess a weapon of devastating might; it can be used by other monsters, but it becomes most powerful when used by its master. Alone these monsters are powerful, working with others they are near undefeatable.