When the Cosmic Portal opened, the whole Universe of Monster Legends was shaken to its core. Every monster that could get hold of some Stardust could build a future for themselves and become stronger. However, ambition often comes at a price.

One of these monsters, only known as ‘The Lord’, wanted to defeat his rivals at all costs. One ill-fated day, he was looking for Stardust so that he could become Cosmic, but the Stardust he found had been under the roots of the Cardinal Forest for too long and it had gone through a transformation, a sort of putrefaction. It had become Lutum.

When 'The Lord' unearthed it, this decay spread like wildfire through all the crystals of Stardust that remained in the Universe of Monster Legends, and a new generation of monsters was born: The Corrupted.