User blog comment:CoolJazzman/Two people behind Sado/@comment-5407918-20130707022908

I honestly think that one is Grimmjow; I'm only really basing this off the way that the sleeve was rolled up on the arrancar only shown mid-chest down in much earlier chapters behind Kisuke, so I can't bee too sure. But with all the crazy happenings going on in the plot right now, I don't think it would be above Kubo to bring Grimmjow back.