Leixein
Hi man(don't mean this in any offensive way would it better for me 2 say mate? Can't believe how an abbreviation of human can be offensive), I have enoyed your book alot just wished u researched konosuba b4 u started theese chapters as u got all background stuff wrong basically either that that this book is basically perfect and now that its done and read it a few time u learn t o accept it and treat this part as konosuba crossed into a rpg world. P.S. your cult stuff is basically correct.
The world after this is Evenicle, its an ero-game that can be found in steam or you can download it for free at f95zone.com I love the girls from that game so i have to make them as harem member. As for the 3rd world maybe Maken-ki? im still considering it though, im re-reading the manga of maken-ki to see how should i approach it in case i make issei go there. The only thing that giving me the headache is the maken skills etc, its pretty hard to list them all. And maybe after the 3rd world i will have Issei return to dxd world to register for the world-class rating game aka Azazel cup ftw! lul
(Aura) is energy which is leaking from body , either living or dead person(being or entity) , so it's form is kinda life or death energy which can't be contained in body , using this as statement we can deduce that [Senjutsu , aka -Sage Art[ can be used to control natural and life energy inside body and also absorb energy from environment , like Nen to certain degree . So senjutsu can use aura and cultivate it use certain methods .