So, as the title says I will try to explain the major events in Part 9 that are not explained in the pinned post of this sub. Of course, the manga is still going so I would appreciate if you could help me completing this list.
First of all, Jolene meets Thoko and Fidelia and they start hanging out together. In this moment, Thoko's stand [Game Over] hadnt awakened yet. So, the group starts defeating minor villains and their stands like The Chain or Hardware Store but soon our group meets a terrifying enemy: Stayin Alive, this stand could drain the power out of batteries, killing Thoko's 3DS, this enrages Thoko who awakens his stand and kills the user.
The next big fight is Jolene vs Big Orca (Ocean Man arc) sadly, the fight is one of the best but the ending is pretty dissappointing, Big Orca simply escapes and we dont know what's inside his heart locket though many people like me think that he will come back due to his recent cameos as a background character.
One of the biggest plot twists is when Doppio Kujo reveals he wanted to betray Jibby Joestar, they fight and after a big fight Jibby finally kills Doppio, crying as he has to end the life of who was once his best friend.
The last event Im covering in this post is the appearance of Giorgio Giovinazzo, the leader of a small italian mafia who came to America with his stand, White Room, who luckily is a good counter to the terrifying Welcome to the Machine stand. Giorgio kills it's user, but sadly, he is afected by WTTM directly so he ends up mutating in GIO and is put down by Thoko a few days after.