User blog comment:Xilinoc/Ch. 562 - THE VILLAIN 2 (Mask De Masculine is a Mexican luchador in a German army)/@comment-24306779-20131219190531

I think this chapter made clear that Renji got a remarkable boost in his reiryoku during the period he spent in the royal palace. That was hinted during his conversation with Rukia at The Eyeball Monk's palace, during which Rukia wondered what the effects of such a reishi-dense environment could be.