The Void Crisis
Before the ejection of humanity into the Void, all humans lived rather peacefully in the Old World. First, they lived across their home planet with relative ease, building cities as they desired and developing each race's individual culture over centuries, or even millennia. As the Void invaded their plane, and then their planet, and then their cities- they were pressed into a corner.
This corner was Maredein, otherwise known as the last bastion of humanity. 'The Void Crisis' refers to the specific moment when the Void broke down Maredein's walls and swarmed the final city, only for most of the remaining humans to be mysteriously whisked away into a colossal rift in the sky. This page will detail this moment, its facets, and the events following immediately after.
The most notable portion of the Void Crisis was and is absolutely the immense rift opened in the sky. To those who went through without losing memory of the event, it can be recalled as a tear in the fabric of reality, a purplish-black cut through spacetime that pulled a temporary, crumbling bridge together between the Old World and the Void.
The rift, despite 'saving' humanity, wasn't all good, though. Few if any remember the passage through, and if they do, they've likely gone mad since. The denizens of the Old World were utterly unfamiliar with magic and mana, and a rift of such a scale is perhaps one of the grandest displays of said magic seen in millennia across most mundane planes. So to gaze between planes of reality-
It does no good to mortal minds formerly untouched by magic. What's more, the process was violent; a destructive force indeed, the rift ripped up and sucked through entire buildings and crowds, rending humans and Voidlings alike asunder. Those who survived are likely to be injured and/or exhausted.
Placement of Humanity into the Void
As far as anyone is aware, the ejection of humanity into the Void was done at random. There is no visible correlation between the Void Crisis and where humanity was spat out- if anything, considering the stark emptiness of their new 'home', it's lucky that humanity landed amongst a cluster of islands and not a cluster of rifts or stars, or perhaps amongst thousands upon thousands of miles of raw vacuum.
What can be said is that the mentioned islands are rich with life, minerals, and resources overall. Whether this is explicitly a good thing for humanity cannot be said yet- as there are bountiful groups of roaming creatures as well, of course- but it's certainly far better than ending up stuck with nothing whatsoever. Alongside the sucked-through ruins of Maredein, the humans have plenty to work with material-wise.