The DIO's Diary item is a item everyone has when you spawn. The current uses are
Dio's Diary + Standless = Standless Overheaven
Dio's Diary + Retro/ The World = Retro/ The World Overheaven
Dio's Diary + Retro/ Star Platinum = Retro/ Star Platinum Overheaven
Dio's Diary + Creeper Queen (Unobtainable) = Steve
Dio's Diary + Whitesnake = C-Moon
Dio's Diary + C-Moon = Made In Heaven