User blog comment:HentaiWithKouhai/Jonathan is Star Platinum Theory/@comment-37571822-20181128165239

This is just a simple theory. That means that Jotaro's fighting spirit is that of Jonathan Joestar. The design may be similar but of course, it wouldn't be true. The haunting him, was Jonathan's body, for the fact he hated the Joestars. That's what was haunting him even if Star Platinum was what killed DIO.