Star King

 Star King (星王 Hoshi-Ō) is a series of Sovereign Monsters appearing Yu-Gi-Oh! S and are based on animals from the Chinese Zodiac.

History
In Yu-Gi-Oh! S, the twelve Star Kings were created as part of "Project Zodiac", an experiment to create the ultimate weapon for the Zwielicht Empire's Duel Soldiers. An accident during the experiment caused the supposed ultimate weapon to split into twelve separate cards, becoming the current Star Kings. After various conflicts within the country, the cards spread out over the world over the course of many years, having mostly been obtained by different owners.

It is said that should the Star Kings be brought together once again, they can be reformed into the ultimate weapon. Such an occurrence is seen as a disastrous event by the Zwielicht Empire, who believes it would be a tool of mass destruction to be used to end the war between countries.

Currently known owners of Star Kings include Yurohi Zwielicht and Reiner Eisen.