User blog comment:Xilinoc/Ch. 584 - THE HEADLESS STAR 3/@comment-1351982-20140611115731/@comment-5693502-20140611150705

Well considering Yhwach's "Soul Distribution" ability and the fact that a person's soul returns to him if he's shared part of his soul with them, I'd hypothesise he might be able to make one all by himself. He must've absorbed hundreds of thousands of souls by this point in time. Maybe he can split off part of his soul to create the Ōken and then will replenish his power by making all of his sons "one with him". Just a thought.

Also, where have we seen this exact expression before ? Same expression, different background and clothes.