"Black 2" Video Game: You Almost Certainly Mean Pokémon Black Version 2

There is no major game titled simply "Black 2." You almost certainly mean:

🎮 Pokémon Black Version 2 (Nintendo DS, 2012)

• Direct sequel to Pokémon Black (Unova region, 2 years later)
• New story, new protagonist, Black Kyurem (fusion), Pokéstar Studios, PWT, Medal Rally
• Paired with Pokémon White Version 2 (White Kyurem)
• DS cart — plays on DS, DS Lite, DSi, 3DS (backward compatible). Not on Switch.

Other Possibilities

• Black & White 2 (Board Game): 2018 strategy board game by CMON
• Metroid Dread (Codename "Project Black 2"?): No, internal codename was "Project M"
• Fan Game / ROM Hack: Pokémon Black 2 Plus, Blaze Black 2 (difficulty hacks)
• Typo for: Black Ops 2 (Call of Duty), Borderlands 2 (Black market?), Dark Souls 2 (Black armor set?)

If you describe the gameplay (turn-based monster catcher, 2D/3D, platform, year), I can pinpoint it exactly.