In the universe Earth 01, we have a world of grimories, mana, magic, etc! Asta and his friends at Clover Kingdom find this strange blue colored portal and does the obvious thing which is enter the portal taking them to another universe to keep them distracted with some "friends". In that fellow universe, Earth 12, Jotaro Kujo, a stand user, finds the old man ALIVE?! Originally the old man is named Joseph Joestar, Jotaro's grandpa, who is supposed to be dead due to old age but he's alive and younger than he's supposed to and they also find a strange blue colored portal that they end up getting in with the other friends in the crew, the portal gets them to Earth 01 and lead with the foes from there. Magna and Luck started fighting a blind stand user and it was unexpectedly challenging but with the team up of Magna and Luck, thry are unstoppable, so the blind man was beaten.
Jotaro and his fellows found this elf guy who's controlled by a magical demon! The battle was really short since it's a 10v1, after a bunch of punches and attacks, the elf was defeated! Asta and his buddies came back to their Earth and met up with the stand users! Jotaro explained to Asta that the elves have been controlled by the demons and the demons are helping a bigger threat and the big threat is Dio Brando, a fellow stand user that seems to always come back! Immediately Dio stopped time and killed Polnareff and Jonathan Joestar, the time was resumed with Dio gone and Jotaro was kinda pissed off by the situation and then he screamed DIO!
Jotaro VS Dio! The unwaited rematch between the two, while that's beginning, Asta and the others went to fight Tori and her army. As Jotaro and Dio activated their stands, Jotaro secretly summoned a golem behind Dio and now it waa time! There were attacks everywhere but as to a surprise Dio missed every sibgle one and Jotaro made Dio go on his knees, with that the golem attacked Dio and he died! Jotaro went to the others to fight Tori, Tori is a stand user and also a shadow magic user. The plan was simple, everyone heavily attacks with their stands and the ones with magic kept using their attacks to stop Tori's shadow attacks but Tori had pressed a button that would distract Jotaro, Asta and John making them go to space to deal with something bigger and they failed, failed miserably! The multiverse had been destroyed but Jotaro and Asta had to fight themselves to win and so they did! Recovering the multiverse, something was different... the univeres combined into one, creating other universes! Jotaro and Asta came back and the battle between them and Tori had resumed!
Jotaro, Asta and the gang were ready to take on their final opponent known as Tori Brando, a shadow magic user and a stand user, this battle would be a bit hard but since it's a 13v1 the battle would be easy as hell! Tori firsts tries to stop space but Jotaro made it possible for certain people to move during stopped time so Tori's time stop was useless. Tori then uses shadow magic attacks but Asta just cuts them in half. Jotaro and Giorno went to attack Tori while the rest attacked her stand, Za Space, and with that plan Tori was defeated! As the battle ended everyone said bye to each other and some created some romance and Josuke used his satnd to fix the area and opened a portal to leave. The magic knights were pleased!