The Lore so Far
This is a video posted by the band that covers all of the Lore of Dema so far, leading up to the "Overcompensate" music video.
What is Dema?
Dema is a fictional place created by the band's lead singer, Tyler Joseph.
FPE
Above is an image of a document titled Failed Perimeter Escape, which ties into the lore of "Dema" and has had many different meanings.
Clancy in Trench
Above is the main character of the "Dema" lore named Clancy. The image shows him inside the continent called Trench.
Who is Clancy?
Clancy is a fictitious character created by Tyler Joseph that represents himself and is the main character of the "Dema" lore.