User blog comment:Xilinoc/Ch. 668 - BIGGER,FASTER,STRONGER/@comment-3219912-20160331163002/@comment-11446176-20160401033157

He had an asauchi when he fought unohana - one he picked up randomly as a kid, and fought as a kid. from memory, he was much older when he met Yachiru, so theres not much against him manifesting her as a spirit, just that she doesn't "interfere" with his battles, since he hates it.

Also, pretty sure Byakuya can use his hands to control his shikai too.