User blog comment:Xilinoc/Ch. 616 - Mimihagi-sama/@comment-5551986-20150219154140

If the Soul King has a similar precognition ability to Yhwach, he must have implemented some form of plan to ensure the world wouldn't be destroyed. There must be a reason he has no limbs as well. If Mimihagi is his right hand, which is coincidentally missing, then wouldn't it be safe to assume he done a similar thing with his legs and left arm? Mimihagi is called a fallen god, maybe the term "falling" relates to it not being his right arm anymore. If so he foresaw the events of his death. Maybe he will become whole again. But either way, Yhwach must have foreseen this.

It's hard to explain but with the King and Yhwach both foreseeing the future, there can only be one outcome, only one can win. They must know if victory or defeat is a possibility. And if the King can see the future, why wouldn't he try to change it? Considering he was around before Yhwach.