To understand the Cheesyverse, one must understand its ruler.
Pyro was the youngest of 7 children born unto the honorable King Telemicus. That is, until young Pyro accidentally set his castle on fire killing his entire family and everyone inside.
You see Pyro absolutely loved setting things on fire, and he would often go around the castle setting small fires while his servants followed behind putting them out.
However, one day his fire-starting was particularly rambunctious and his servants were unable to keep up. This led to the horrible castle fire that left Pyro next in line to rule the kingdom.
Now a king, Pyro determined that his arson streak would need to be controlled. In his first decree as king, he declared that all burning would need to be done in one central location outside the castle walls, and The Burn Pit was born.