This hack isn't really active anymore unfortunately. I would like to build another hack with custom paralogues at some point. But if I go through with it, I'll likely build everything from scratch.
When I made this hack, I used some kind of convoluted methods to edit the chapter/character tables. Specifically, I moved both tables to new offsets. Nightmare modules use hardcoded offsets, so the RainThunder's fefates-tools won't work unless you edit the modules to read from the new table offsets.
You'll need to rename @E to @U for the European version.
Aw man that's a bummer, I was even about to submit an idea I had for another paralogue, but that's probably not going to happen now.