This is something that I made for my personal use that I thought I might as well share. It’s a patch that allows you to play English FE8 with the original japanese difficulty.
During localisation, they decided to make the game even easier than it already was by buffing playable characters growths/bases and reducing enemy autolevels across all difficulties, among many other minor changes. This patch reverses all changes made.
Here is the reference that I used for the changes if you want to see specific details:
I also implemented the standard qol patches (visible growth rates, danger area, hp bars, etc) as well as growth modes select. The credits for the qol patches are in the dropbox. Patch to an unmodified FE8U rom. If there are any discrepancies, let me know and I’ll remedy them.