Final Fantasy VI T-Edition

I really want to understand how the expansion of the enemies and esper lists were done.

I've already done a monster expansion test (see this post). I'm really impressed about FF6-T items expansion (which I tried to copy but it's a nightmare), tilesets expansion, maps expansion, music player and monster expansion given the lack of Japanese tools to edit easily those, unless Tsushiy had the help someone that coded special editors. I know item expansion was made by someone else as he used a Japanese base ROM for his project that had already a lot of ASM improvements in it.

I have the Japanese music player ASM file somewhere, it's just really hard to cross-reference the $C3 routines hook-ups since Japanese and US $C3 routines are not at the same offsets in the disassembly, there's always minor to decent (~0x200 bytes) difference in a routine starting offset when you compare both.