Undead

The Undead are a race of monsters in the fanfictional American Kamen Rider Series Kamen Rider Spade Warrior. The story of the Undead is the focus of the series as they were created 10,000 years ago in the form of a stone slab called the Stone of Sealing, to "kill" each other in a free-for-all battle royale known as the Battle Fight, with the winner granted a wish to alter the world.

The 52 Undead represented 52 different species & battled so they can wish for the species they represent to rule the Earth, while the Joker represented death. The losers would be sealed by the Stone itself. The winner of that battle was the Human Undead & the world has been populated by humans ever since. In the present, human archaeologists discover the sealed Undead & a maddened Sidney set them free by mistake. However, the new Battle Fight was a front for a sinister plot by BOARD's chairman. Among the Undeads, there are several specialized groups: the Category Aces, the Royal Club, & the Joker. True to their name, Undead cannot be killed as they are manifestations of different species & thus must be preserved for the next battle, so they had been given them true immortality.

There are 53 types of Undead, the same amount as a standard deck of playing cards with a single Joker.