The Sovereign's Core [Plot; Prelude]

The Digital World is one of great power, but that great power comes with a risk. Every Digivolution takes its small toll on the world, and when Megas and Super Megas are able to let loose enough power to tear away at the very fabric of the world, 'something' needs to keep it in balance. Left unchecked, the constant strain on the world would eat away at the edges, until all that would remain is a corrupted, unlivable mess of a world.

The Digital World has its own response: The D-Reaper. Wherever corruption takes hold, this entity is sure to follow - and in the current Digital World, in its current form, its just an accepted part of life. A red lichen might grow when the sun's rays beat too hard against the stone of the Valley of Dragons, or short shoots of silver grass might take hold over rotted areas of the forest, or in the aftermath of fights of the Dark Area. It is never more than lichen or a weed, easily burned away by the efforts of a Meramon...

... But that was not always the case. The D-Reaper, though it stifles corruption, also serves as a corrective force in the Digital World. In ancient times, the world fell into a cycle of prosperity and ruin, until, in one age, the Sovereign of the world gave their sacrifice, establishing and hiding their own cores in different parts of the Digital World:

Ebonwumon, of the forest.
Azulongmon, of the desert.
Baihumon, of the frozen north.
And Zhuqiaomon, of the lands of darkness.

As long as their cores remained, their powerful presence would lighten the effects of the strain on the Digital World, establishing a secondary defense against the very corruption that lie against it. Under this, the D-Reaper exists only as a small measure, a natural defense to heal against the small 'scabs and burns' that the world would receive on a regular basis.

But perhaps all this did was delay the next cycle of corruption. As Zhuqiaomon's core starts to give way in the Dark Area, the current world is reminded of the chaos that was once considered inevitable...