User blog comment:Xilinoc/Ch. 630 - The Twinned Twilight/@comment-3230060-20150611160732/@comment-5693502-20150612101802

Nope, still don't know what Mayuri was penned for, but it probably has something to do with Shutara.

I don't think Isshin or Ryuuken are coming anymore (unless Kubo has another plotkai up his sleeve).