Never

Within the world of white, Dyon remained kneeling as his master began to recount her story.

"There are many things within my memory that I've hidden from you. But, there are many things that I chose not to as well. One of those things is quite important to the lore of this universe… The concept you know as heat death." The 25th White Mother began.

Heat Death was a concept that Dyon had learned of from the mortal world, but it seemed to have a very strong place in the martial world as well.

Essentially, there were two main forms of energy. Energy that is capable of being used, and energy that has lost its use.

Over time, usable form of energy decreases, while unusable forms increase. The end result would be a world with no useful energy whatsoever… A catastrophe of a world.