There is no functional PS4 emulator for the public that runs commercial games smoothly. If a site offers a "PS4 Purā Purā ROM," it is either a fake .exe virus or a decrypted backup that requires a jailbroken PS4 (firmware 9.00 or lower). For 99% of users, that ROM is useless.
The base v1.0 ROM is broken. It has major frame drops, missing voice lines, and a game-breaking bug in Chapter 4. To play properly, you need the base ROM plus the v4.0+ update file plus the DLC. yokai watch 4 purapura rom top