User blog comment:Xilinoc/Ch. 671 - The Perfect Crimson 2/@comment-24726378-20160422170021/@comment-28285364-20160423175929

I dont believe it works like that. It's always seemed like they could asorb the reishi that was in the air or even constructs such as buildings in the serietei but i don't remember even Uryu asorbing the reishi from a bankai. Otherwise he wouldn't have had to use his glove against Captain many faces in the soul society arc. Just how i interrupted it anyway.