Requiem of the Brilliant Diamond [OC]

I have the following doubt. If the stands that become requiem can fulfill the user's greatest wish, as seen with Chariot who protected the arrow and changed souls and GE with defending Giorno (sorry if I don't say it right).

In a hypothetical case where Josuke had managed to get SD to come into contact with the arrow in the final fight against Kira, what abilities would he have obtained?

Image credits: TT: @hey__dd