i noticed i missed some things in the op this is what you need for your fbi (cia installer) problem https://gbatemp.net/threads/release...ect-generator-jpn-usa-eur-chn-kor-twn.391525/
Thank you! That's the tutorial that I was looking for, I used it when I have my o3DS (that was stolen, and now I don't have kernel access for my personal device ).
I'll try it. About RxTools devmode, everybody agree with the fact that it is "Pasta Mode" in the "Advanced" menu? (or am I doing a terrible mistake here?)