Been following that SG x JoJo set and it was clear the last would be Parasoul as Johnny and I'd say the artist was pretty clever by adding the bike, both to stay with the SBR theme (and Johnny's condition) and a "prop" of Parasoul's.
And speaking of clever, kudos to you for coloring the sleeve's wrist as wristbands; Well shows she can have palettes with mostly naked arms that don't look really awkward.
Side note, while color is something that is never set in stone in the JoJo series, if you are aiming for a Johnny Joestar palette, he's usually portrayed with blond hair (I think it might be better as is though).