I mean, we ended the Sacred Timeline the Titans were so adamant about creating and sustaining, we had multiple alternate Timelines attempting to fuse into and invade our own, we had an alternate reality that was fused to ours for months, if not over a year …
We can see the Void-touched individuals within the ‘layers’ we can reach by exposing ourselves to the Black Blood can survive indefinitely in there. Who’s to say the Arathai aren’t just people who wandered into a Light-infused Layer and never realised because unless you go super deep and ‘lose’ your connection to your original, native layer, the landscape and terrain remains roughly the same, just distorted somewhat, and that’s because Void is All Things Simultaneously, whereas the Light is One Truth Only.
The Black Empire(s) were how the Void attempted to establish a permanent connection with Azeroth despite the Layers theory. Beledar and similar Light-crystals might be how the Light attempts the same thing, and the Mantle and the Titanic Installations might be how the Titan do their version.