This is a modified version of gringe's FE6 localization patch detailed here:
The dialogue and story/script remain unchanged. All this patch does is update the names of all the characters in both data and script to match those localized in the Fire Emblem Heroes Choose Your Legends event. So now Allen is Alen, Wendy is Gwendolyn, etc. As always, let me know if there are any bugs and errors past the first chapter, and enjoy!
EDIT: Thite is now Thea, and you can apply this patch onto a clean FE6 rom.
FE6 Name Patch v2.1.zip