Millennium Kingdom

Millennium Kingdom was a Guild that existed in YGGDRASIL.

Background
The Millennium Kingdom's guild symbol takes on the shape of a Crane.

The Craftsman of Dwarf Arc
When Demiurge inquires how far into the future his master has planned for the Sorcerer Kingdom, Ainz would then recall about there being a guild called the Millennium Kingdom. Ainz believes that the idea of the Sorcerer Kingdom existing a thousand years from now is comparable to the Millennium Kingdom. He discern this information passed down to him by Yamaiko regarding the meaning behind what their guild symbol represent.

Trivia

 * According to Yamaiko, cranes were said to live for a thousand years in mythology and it is supposedly used to symbolize the Millennium Kingdom.