Mass Sprite Sheet Expansion Battle & NPC

This might be a problem with the palettes. Try setting the same palette (one that works) to all character sprites and see if you get them to load.

Egger says in his ReadMe

In battle, however, character sprites "give away" a partition of their palette
to other, miscellaneous sprites, such as the hand cursor, damage digits, and
so on. PC sprites only use the first 12 colors, while the other sprites only
use the last 4. So, if you create a PC sprite that uses the last 4 colors,
those colors will show up as colors from the hand cursor or something else,
instead of how they're supposed to.

[...]


So, even with this patch, you are still limited to 12 colors, but they can be
any 12 of your choosing.

Seeing as Egger's patch detects your colors and creates a palette by itself I think you might need to be careful that the sprites do not contain more than 12 different colors.

Then I also noticed some variables that might worry in his code:

Code:

LAST_BASIC_SPRITE_OFFSET .EQU 22        ; 22 sprites are used as battle sprites in the original game. Gestahl
                                        ; is number 22.
NUMBER_EXTRA_SPRITES .EQU 32            ; In case someone adds new battle sprites, we'll handle this (in a very
                                        ; slightly less efficient way). 32 should be more than enough.

So battle sprites above Gestahl are handled differently by Egger. Therefore this might be an issue or conflict with Eggers patch. I would recommend doing the expansions first on a vanilla game and adding Eggers patch after if you need the dynamic palettes.