Because the game is PS2-exclusive, the only sanctioned way to play it on PC is through – but strictly only if you own a physical copy of the original PS2 game . Ripping your personal disc to ISO format for use with an emulator is legal in many jurisdictions (including the US under fair use provisions for backup purposes, though laws vary by country).
Since Onimusha 4 was not officially released on PC, playing the game on computer requires the use of emulators or workarounds. Here are a few options: onimusha 4 pc download
Searching for (officially titled Onimusha: Dawn of Dreams Because the game is PS2-exclusive, the only sanctioned