There is a patch in FEBuilder that can install the skill system with no boss rush. If you want to use build files, do the following to remove the boss rush chapter:
- Open the main build file and comment out the events and maps sections.
- Open “./Text/text_buildfile.txt”. Remove the Boss Rush entry at 0x160 as well as the HouseText and VillageText entries. Renumber the other entries with new offsets starting at 0x0D4C (for a vanilla ROM). Do the same for any files that are referenced in the text_buildfile.txt.
- Delete the textentries folder. Run the textprocess program on the text_buildfile.txt and verify that the new event files were renumbered correctly (none having indexes lower than 0xD4C or your chosen starting point).
- Open "./Tables/FE8 Nightmare Modules/Chapter Data Editors/Pointer table editor.csv” and change the “0x04 Prologue Map” value to 0x81b76f4 and “0x07 Prologue Events” to 0x89e863c.
This should allow you to start a new game like normal.