User blog comment:Xilinoc/Ch. 586 - The Headless Star 5/@comment-24913480-20140625154453/@comment-24913480-20140626170325

I'm aware of that limitation, Yashael, but since it was stated by Bambietta and she was just refering to herself (and, I believe, to her fellow sternritters), it is possible that Yhwach can indeed make such a combination. At least for now, I don't see any other threat towards the Royal Guard and the Soul King: the Zero Division's combined power surpasses the total might of the Gotei 13 (including captain Yamamoto, I presume, that's what has been stated) and the Soul King is probably at least as strong as ButterflAizen, so... Yhwach doesn't seem to have any other option, at least for now.