who created the borderlands in alice in borderland

The Borderlands in "Alice in Borderland" were created by an enigmatic entity called the Joker, also known as the "Watchman." The Joker is not portrayed as a ruler or god but as a force that fulfills the gaps between time, life, and death for humanity. It controls the Borderlands and uses games to test individuals' will to live, making the Borderlands a sort of purgatory or liminal space between life and death.