Quoting the Wiki here, acknowledging it is not itself canon, "Arkat cursed it with the Curse of Cleansing into becoming a foul chaos infested hell". Away from my books at the moment.
Refer to your nearest flat-Earth pundit for their latest theory. I have a fondness for one propounded at a recent conference, that the world is flying upwards. 🤣
We know of four forms/parts of Ralzakark, which leads me to wonder something. A lot of the time Gloranthan figures have seven components.
Are there another three yet to be revealed?