User blog comment:Xilinoc/Ch. 611 - The Soul King Dies (edgy as ever, Kubo)/@comment-5693502-20141226160113/@comment-6904925-20141226170845

Possibly a between the shredding and by-product, I say like Yhwach can separate parts of his Spirit to his subordinates, the Soul King could do the same, say he found a woman and placed part if his spirit in her, resulting in Yhwach birth.

As for the Soul King, I don't think he is the "OP fighting god type" he just holds everything together, its like in Shaman King (I'm not sure you seen it or not) when Hao reached the Great Spirit, the Great Spirit was just a source of power that kept everything in balance, like the Soul King.