Board Thread:Theories and Speculation/@comment-294840-20170617143219/@comment-25632268-20170617145421

As far as I know, only Guren had Crystal Release and she is a filler character, so non-canon. So it may, and probably is, just something made up by Studio Pierrot and they never bother to came up with explanations about what it is. Though I think this filler arc came out before introduction of Onoki and Dust Release, so it is rather unlikely it is Kekkei Tota.