It wouldn't be better that we talk about this Spin-Off in the Discussion of Others Topics's thread or that it got a discussion thread completely dedicated to it?
I have make the Discussion Thread for Junior Highschool DXD if someone is interested:
https://forums.animesuki.com/showthread.php?t=159717
For remain more in the Topic of this thread what are your ideas about the Malebranche? You think that Ishibumi would allow to the each of the Malebranche have a particular personality and unique abilities or they wouldn't be so much differents from each other?