Yuko mindbroke him. Of course Gen can't look at Reiji in the eyes when he looks like his mother so much. I wonder if the sources of this crossdressing is exactly that.
I wonder how Faputa fairs against Nishagora in the white whistle form.
Also I just realized while browsing around the wiki that Srajo (the white whistle woman) is the one that was sneak peaked with the plague doctor mask. Wonder what's up with that?