Was born, shaped by the void into the image of their firstborn son. Sorry for the text wall and all that it just feels weird to write all this stuff and give everyone zero context whatsoever.

Thus no infection, so Hallownest is a pretty peaceful and prosperous kingdom. Second point of canon divergence is that the White Lady and Pale King had a weird plant child who turned 18 and then died of mysterious illness that rots him aliveTM. So they threw him into the abyss and thus pure vessel