Formaggio is one of the people trying to kidnap Trish to figure out where and who the boss is. Its likely the group he was part was trying to gain power and didn't have noble intentions of our heroes. His stand can shrink things than expand them
Mario Zucchero is tricksy villan but once you figure out his secret to his stand its so easy to take him out and torture he had to endure from the crew burn into his eyes so much dancing.
Terunosuke Miyamoto is tricky enemy he just has to makes an opponent afraid for a second he can trap person into a piece of paper however if he can't he will get one heck of beating.
Mazao Kinoto himself didn't want to help Kira but his stand has a will of its own and will attach to people who see it and if someone sees it the person's who's back its on will explode killing the person.
Toyohiro Kanedaichi is an enemy stand user his stand is a power tower yes it is true and he can't control it whoever is inside of it is stuck and so he spends the rest of time stuck there gotta say must be tough durning winter or the raining windy season.
Yuya Fungami is powerful tracker and his stand has a very long range and can travel at 80 km I think or was it miles? Josuke knocks some sense into him and gives him a better perception of things and he changes his ways and helps in the final battle.
Ken Oyanagi is a foe that the Rohan fights in rock paper scissors his stand ability kept them doing this over and over again till Rohan figure out a way to stop it and its great.
Tama the cat plant he starts out as a cat but is killed by accident and bury than becomes a plant Kira finds it of use and keeps it alive than puts into his stand to give him self another ability so thats 5 abilities his ghost dad helping this cat plant and the 3 abilities he has
Yoshihiro Kira he is our villain's father of part 4 and ghost he helps cover his son's crime out of fatherly blindness I mean love he goes and finds people that he gives stands to and might have worked for Dio in exchange giving his son a stand and he help Kira in final battle.