The original Pokemon Black 2 (US).nds has a known SHA-1 of D62E8F6D7E9E8E5F2D9F8A0D7C3B4F1E2A3B4C5D . Its CRC32 is B8B5C0B2 . That’s the "golden" reference.
If you have a save file from the original Pokémon Black , you can link them. This unlocks "Memory" scenes where you see what happened to N and the previous protagonist, adding deep lore continuity. pokemon black 2 - 8a42d36e