searching for a world that doesn't exist

Minecraft alternate reality game created and popularized by Minecraft Youtuber Wifies.

AveryTheMayo found a laptop in a school locker with Minecraft preinstalled. As he played in the world, he discovered some prebuilt structures underground. He posts a video online asking for identification help.
The video flashes a deciphered code for a Google Drive link that contains footage of gameplay in the world and a brief background. This footage was recorded and edited by d3rlord3 who then discarded the laptop where Avery found it.

The structure is suspected to have been built by the king in yellow (searching for a world that doesn't exist) who also encourages d3rlord3 to find a secret that then drives him insane.