Vrykolakas Lore

It is often asked by those with the knowledge to do so why all of the major Invaders present in the world are well adapted to work with the world’s sapient life. Although far from benevolent, none of the more powerful Invaders are purely destructive in their behavior or approach to reality.
This is odd when looking at the lesser Invaders that appear in the Bleak. While some are socially adept, the majority are alien creatures that cannot blend into the local life. Yet others are purely malevolent, killing everything they encounter or rendering the environment hostile to any native life.
A possible answer to this question lies in the Vrykolakas and their patron. Before the Founding War, something manifested within the Bleak, an Invader that appeared much like the rest of its kin. However, it quickly proved itself to be something beyond.
The Invader rampage across the Bleak and found its way to the Mortal Realm, already far stronger than it had first appeared. Among the life of the Mortal Realm, it cut a wave of death. And in its wake, the dead rose as something far more terrible than the undead born of antimus.
These creatures killed and spread, extending its hunger for destruction like a disease. And as it killed, and those it killed killed in turn, it grew stronger. Before long, it was evident to the early Denizens of the region that this creature was a force of death that would only grow as it killed.
One of these early Denizens who served as the defender of their people attempted to fight it, taking their warriors to battle the monstrosity. They fought, and all the Denizens kin died. However, their leader managed to slay the creature, only to find it unable to truly die.
As is inevitable when a mortal faces a god like Invader, the Denizen who had briefly won would have lost in the end, if not for intervention. The Unborn God appeared to the injured Denizen as they succumbed to their wounds, offering to save them and help contain the creature.
Accepting, the Denizen that would one day become the High King became a Chosen Of The Unborn God. The Unborn God used the connection to their new Chosen One as a gateway to target the Invader, binding it into their Chosen One’s body.
The Invader was indefinitely contained, the power of the Unborn God stopping it from continuing its growth unto the world’s destruction. However, despite the Invader’s imprisonment, its servitors remained, enemies of all that is.