hi if you have questions about programming sounds you can ask me (i was called mr prophet in the music business as the prophet 5 and ppg wave are my mainstay hardware for years)
yes unison mode triggers all available voices under one key , in real prophet 5 its 10 oscillators 2 per voice , in prophet v it depends how much voices you assign to the plugin (can be more than the hardware)
the pro one and prophet 5 were very different beasts (there is always the misconception that the pro one was 1 voice of a prophet 5 wich isnt true) first the CEM curtiss chips
that were employed in prophet rev3 were not the same as in the pro one , not for osc and not for filters (the prophet 600 and T8 had the same chips as the pro one) , the filter
of the pro one was slightly overdriven at output , again not on prophet 5, the 5 employed a unique way of modulating voices in poly mod , the result of modulation was
changed polyphonically by the amount of voices that were depressed on the keyboard
turning japanese indeed uses the 'falling bells' patch of the prophet 5 (a sound that was used a lot by gary numan as well) the ring mod main osc frequency in that is sweeped by the filter envellope, adjust the depth of the sweep in the poly mod section, you can ask for a patch that explains it more in depth if you cant find it yourself