So I got this working in Citra, after many hours of googling and a bit of dumb luck. To get it working, you need FEFTwiddler, the unit files and the release folder. Copy the contents of the Release folder into 000(et cetera) > extdata > 00000000 > 00001794 > User. Back up the files you are going to replace there just in case. Then open FEFTwiddler, import the characters in and that's all.
@Omegablu Idk if you're really still active, but it also bears mentioning that Severa's unique mercenary has sword and LANCE proficiencies, not sword and axe. I'm a relative novice, but is there a way I can go in and edit that? Thanks alot for your hard work btw, It's great having some of my old faves in.