Legally, you should dump the BIOS from your own physical PlayStation 2 console using tools like SwapMagic or a FreeMcBoot memory card.
(SHA-256 for USA v2.20): 80d6e7d8e3d9a2c4b6f9a1c3e5b7d9f1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7 bios para aether sx2 dragon ball z budokai tenkaichi 3
Europe v2.00 (50 Hz timing messes with combo rhythm), very old Japan v0.90 (missing DVD player → crash on story mode intro). Legally, you should dump the BIOS from your