If you are looking for an official localized experience, the Castlevania Requiem bundle on PlayStation 4 includes a redubbed English script (and subbed options), though it lacks a full Portuguese voice track.
Many dubbed playthroughs are presented in 1080p at 60fps using emulators with graphical filters to modernize the appearance of the 2D sprites. Castlevania_Symphony_of_the_Night_(BR)_(Dublado...
Several creators have uploaded "Full Feature" or "Completo" series that cover the entire game, from the opening Richter vs. Dracula fight to the True Ending in the Inverted Castle. Technical Details & Availability If you are looking for an official localized
The dubbing usually covers main story cutscenes, including Alucard's encounters with Maria Renard, Richter Belmont, and the Master Librarian. Dracula fight to the True Ending in the Inverted Castle
You can see examples of the Portuguese AI dubbing and full gameplay walkthroughs in the following videos: