I wanted to be able to change the Pokémon that are recorded upon defeating Gym Leaders, that you can check from an NPC in Lacunosa Town (BW/B2W2), Laverre City (XY) and Mossdeep City (ORAS.) Couldn't find the info online, I doubt anyone cared enough to figure that out, so I did it myself.
Offsets:
BW: 21258-212B7
B2W2: 2115C-211BB
XY: 1D82C-1D88B
ORAS: 1E860-1E8BF
Twelve bytes per badge, in the same order as the badges themselves. Two bytes per Pokémon